Very good lineup for next and I really hope Metroid is also released next year, i am so ready for that game.

Remember how the release schedule looked in 2017 when Switch first launched? At E3 it changed heavily same thing for next year, we'll also have a usual ND in Jan/Feb.

Not to mention that they're far from done selling.

This of course not full 2019. lineup, but this is much more and quite stronger, than we know about this years lineup in same time of last year.

For instance, Smash Bros Ultimate was announced in March/April of this year and Pokemon Lets Go in May.

Nintendo in 2019 so far should be this:

Fitness Boxing NA (3rd) (releases in Europe in Dec 2018) [They are not publishing this in Japan, Imagineer is self-publishing it in Japan.]
Super Mario Bros. U Deluxe (1st)
Yoshi's Crafted World (1st)
Fire Emblem: Three Houses (2nd)
New IP = Town (working title)
Animal Crossing (working title)
Luigi's Mansion 3 (working title)
Pokemon: Switch RPG

They are also publishing Dragon Quest Builders 2 outside of Japan in 2019 too.

Maybe, point that Metroid Prime 4 and Bayonetta 3 are not confirmed for 2019.  doesnt mean those games want come next year (Metroid Prime 4 and Bayonetta 3 are TBD from their reveal). This are just currently confirmed 2019. games, its not full 2019. Switch lineup list in any case, we want know full 2019. lineup before E3 2019. earliest.

2019's first-party line-up could be great and will be stronger than 2018 in terms of original titles. Luigi's Mansion 3 and NSMBU DX should hit the 5 million mark, and Animal Crossing and Pokemon will shift over 10 million copies, so it's commercially strong, too. Games like Yoshi and Fire Emblem might land in the 2-3 million range.

Personally I really hope they can get Metroid Prime 4 and Bayonetta 3 out next year. If you then add stuff like Town and Daemon X Machina, then the overall first-party line-up is varied and interesting, with room for more announcements.

If you add Sun/Moon + Ultra Sun/Ultra Moon it is more like 24m and it's still selling.  I wouldn't be surprised if this new Pokemon game sold like that.

I wouldn't add USUM to SM sales for gauging the possible success of a new Pokemon. It is a second edition and sells also on people double dipping. We could expect something like this, if there will be released a Ultra-version to Let's Go. But I think that is unlikely. Next year we have the next mainline Pokemon, then I expect a remake with the new engine and after that maybe an ultra version for the mainline Pokemon.

Yeah, I was referring to the mainline Pokemon game next year.  I thought that is what you were referring to, since you mentioned 2019.  Also I understand double-dipping, but I've never seen percentages for that, so I am not sure how much occurs.  If I had to guess, I would think first month sales of the Ultra version are where you get most of the double dipping and then after that it is mostly new people who just get whatever Pokemon game is current.