Is Metroid a system mover?

Heck, the first Metroid Prime restarted development from scratch several times from what I remember back in the day. This really isn't anything new, even for this particular (sub-)series.

Ouch. Even though I'm not a Metroid fan, that stung. I can only sympathize with what Metroid fans are feeling.

While this sucks to hear, at least Nintendo was honest with us and they are demonstrating that making this game the best it can possibly be is a top priority for them, which is something I think Metroid fans can find solace and comfort in.

Goodbye Metroid Prime 4 on Nintendo Switch.  Hello Metroid Prime 4 on Nintendo Switch and the successor to the Nintendo Switch.

Seriously, I can't see Nintendo keeping the game solely on the Switch six years into its lifespan.  It's most likely going to be a multi-generational game like Breath of the Wild and Twilight Princess whether people like it or not and I can't fault Nintendo for it.  This also explains why Retro ramped up their hiring efforts recently.

Now there's your Janruary Nintendo Direct with Metroid Prime 4 in it. Happy now?

I think they've already got the next game/sequel with the Breath of the Wild formula penciled in for that slot given how wonderfully it worked out for them with that game and Twilight Princess. 
The very best fans could hope for is that the game will be ready to go by 2021. If not, then I think the best option for Nintendo would be to pull a GTA V where they release the game as their big Switch holiday title for 2022 and then port it a year later to Switch 2 to extend its legs and give it a better chance to sell more copies.

On another bright side, I think this opens the opportunity for Nintendo to do an HD remaster of the Metroid Prime Trilogy for the Switch.

A 2019 Metroid HD trilogy remaster at full retail price would be great, but I wouldn't mind if it was $30 ala carte on the eshop (similar to RE: revelations).

Now I can help but ask the question:

What the hell has Retro been doing these past 5 years between Tropical Freeze and now?
Since they'll be mostly/all in on Prime 4 moving forward, whatever they were working on is either done, near completion, or got scrapped.

I know that this is an example of a good treatment of the franchise by Nintendo, but I can't help but have flashbacks to that hilarious thread where the OP went on to blame all Metroid fans and didn't give Nintendo an ounce of criticism at their treatment of the series, acting as if they have never mishandled the IP before. It's especially ironic now that the one thing Metroid fans had to look forward to is now basically delayed another few years after already having to wait an eternity.

That being said, I think this is good news all in all. It does make me a bit worried in some ways. For example, because Nintendo probably spent so much money on the previous version of the game already, will the budget of this new version be restricted? Does Retro Studios still hold on to the same staff members that made the original trilogy so great? Will this ultimately accumulate to an entry which is "more of the same, but in HD" and doesn't take risks with the Prime formula?

But honestly, the fact that Nintendo was so sincere and direct, and even made a video about it(!), makes me more optimistic than I already was after the original version had been in development for years. I'm actually more excited at this new version than the prior one, if Nintendo's standards are that high.