It hasn't been issue on the Switch thus far. Nearly every Nintendo franchise across the board has had its best selling game on the system because not only has the studio had the proper marketing, support, and resources behind it to do it. It has had the foundation successfully put in place where that game is automatically starting from a position of strength, rather than weakness. Right out of the gate, it is in a position to where it can achieve those numbers and Metroid should be no different. Fire Emblem, Pikmin, and Xenoblade aren't exactly A-list franchises either. But all three of them are not only succeeding on the Switch, they're thriving. That's what happens when you have a system that is white hot like the Switch is, everything sells. Because the casuals who love the brand will automatically associate the game with the brand and THAT'S where those other buyers come from. So, if Metroid DOESN'T sell, while everything else is... That is not a good look. At all. 

Yes, all those franchises experienced some increase in sales, but to say they are "thriving" in my opinion is quite a stretch, they did better than in the previous entries and that's it.

Also, I don't think any software is guaranteed to sell well until people get to actually see the game.

Pokemon is arguably the second biggest Nintendo IP and even being released on Switch it won't be the best selling Pokemon, because the game is trash. Not even the massive amount of money Pokemon Co spend with marketing (probably much more than the game budget itself) was enough to change that

Edit:Also NSMB U, not even adding Wii U sales will be the best selling 2D Mario, so here you have it, the sales of any software will depends of the software itself and not only its platform 

Let's just calm down and wait. Even if Dread don't outsell the previous entries doesn't really mean the franchise is doomed as you imply

The sales of this game will indeed say a lot about the series' appeal. It has pretty much everything going for it as far as it can being a 2D entry. Besides the NES original, no 2D Metroid has ever reached 2 million copies sold. Just breaking that barrier would put it at the third highest selling entry ever, 2D or 3D.
I agree with PAOerfulone for the most part; you really couldn't ask for better circumstances. I for one will be supporting it for sure.

When was the last time Pokemon sold over 20 million, though? The last time that happened before Sword/Shield did it was in Gen 2, (Gold/Silver), back at the tail-end of the original Pokemania Phenomenon, back when Pokemon was the biggest thing on the planet. And now, it's just 2.01 million units away from passing Gold/Silver for 2nd on the all time list. And who knows? Sword/Shield has shown to have much better legs than Pokemon games of the past. If it doesn't reach Red/Blue, it could come pretty damn close. And that would all be IN SPITE of the quality issues that you mentioned... So, the software itself doesn't seem to be that big of a factor, albeit an important one, just like the system it is on, among other factors that I described.

And I'm not sure what you're trying to say regarding NSMBU. Are you saying it WILL be the best selling 2D Mario game even without the Wii U sales? If so, you're just proving my point.

But, yes, you are right that the software itself is an important factor. But, there are other factors that are just as important into making it a hit, which I have detailed in my last 3 posts. All of which Dread should have going for it, which is why it would be a disappointment if it doesn't achieve similar feats as other games from other franchises that have been in its position.

You say no software is guaranteed to sell well until people have actually seen the game. Well, we've all seen it and the reception has been overwhelmingly positive. Quite the opposite from Sword/Shield where that game was panned by a lot fans pretty much from the start. Dread clearly passed the '1st impressions' test with flying colors. And if you've played Samus Returns, then you have a very good idea of what the game is going to be like considering it's made by the same developer. But unlike Samus Returns, this is on a system in its prime, a system that's white hot, and being positioned as a major, top-tier 1st party entry on that system. So, it should achieve record-setting numbers by the franchise's standards. If you're a Metroid fan, I don't see how you wouldn't demand anything less.

I can basically picture in my head the drops in the visor as i move the cammera to watch the rain falling, Truly Metroid Prime was/is a Masterpiece in all aspects of it's craft, while other games have been recognized by their cinematic storytelling almost rivaling that of movies, i always tought that Prime achieved the perfect gameplay immersion storytelling, and i think that all the hours i spent not only advancing in the objectives but also collecting all logs, expansions, or just standing admiring the enviroment like the rain drops in Talon overworld, the birds flying above the chozo ruins main plaza, the snow falling in the camly phendrana drifts or the chozo statuary and architecture in several areas  are one of the most fullfilling experiences i've ever had.

i can't choose a favorite as the music was also amazing and went perfectly with the areas in which they appeared:

Chozo ruins

Phendrana Drifts

But also since the very beginning starts mangnificently with this eerie theme:

Is there any confirmation that special editions have actually gone on sale?  Best Buy's website says coming soon.  As does the Metroid Dread official site.

Amazon has it listed as "temporarily out of stock."

I meant NSMB U shall not be the best selling 2D Mario even when we combined Wii U and Switch sales, simply because it's not a very good 2D Mario. It may not surpass New Super Mario Bros for DS either

But you are right things are doing good for Dread, that's why I believe it has solid chances of being the best selling 2D Metroid yet, but it fall short I still don't think it's enough to "doom" the franchise. Metroid treatment has been abysmall, at this point the franchise isn't that popular. I agree fans are satisfied and happy, but fans aren't enough. Dread trailer has only 800k views on YouTube, that's solid and about 2 times bigger than let's say SMT V and WarioWare, but it shows Metroid brand is closer to this range of popularity (SMT and Wario) 

Even if the fandom like it the casuals just don't care and very likely keep not caring until the game came out  and have great reviews and great WOM

Does it means the franchise has no potential? Not really, it just means GP isn't really aware or bothering with a 2D Metorid yet and maybe just one game won't be enough to turn things around. I'm just saying to not be so harsh if Dread does not meet your sales expectations

Well, you laugh, but even the chance for your statement isn't zero, ain't it? 

You examples don't make any sense.

Pokemon S/S is selling huge numbers. Yeah it's not going to beat the original Pokemon, but no Pokemon has come close to that, and S/S will obviously be the second best selling Pokemon game ever. So if you think it is a terrible game that pretty much proves your whole argument wrong. Of course it isn't a terrible game, but anyway this example doesn't make sense.

And NSMBU....ummm there are numerous 2D Mario games that NSMBU:D won't even come close to, so I have no idea what you're talking about there. But considering it was a low marketed port that Nintendo just threw out there in January and isn't particularly great for a 2D Mario game its sales have been phenomenal.

Basically, Nintendo IP have monster sales on Switch. 

The problem with Metroid Dread is its a $60 game. At $40 (which is about what feels right for a first party 2D side scroller not called Mario), I think it could sell around 3+ million which would obviously be great for a Metroid game. At $60 I definitely see this being limited to 1.5 million, and the only reason it'll get that high is because it's on the Switch. I certainly won't be buying it at $60 even though I'd love to play the game, and I'm guessing by the time it is on sale for say like $30 I'll already have MP4 and won't even be bothered about getting Dread. This is gonna be like Link's Awakening remake. Great game that lots of people are excited about but launching at $20-$30 higher than what makes sense so sales are going to quickly die after the first couple weeks on the market.

Franchise is of course not doomed no matter what happens, but sales will be low because of pricing. If they priced it right, combined with the pent up demand for Metroid, plus Switch's install base, I think it'd sell really well. MP4 will be the true test of Metroid's popularity. With the critical popularity of the Prime series, the years long wait for it, and Switch's well over 100 million user base by the time it comes out, MP4 will hopefully go after 10 million in sales thanks to the Switch boost.