The studio that made that is kinda dead, unless they can wrangle some of the key people.

That has to be what From Software is working on, right?

Nintendo is trying to show that M-Rated titles can sell well on the Switch.  Making a sequel to a niche horror game isn't going to help their argument.

FE 2018 is going to be interesting.

They could make an AAA Eternal Darkness instead of a niche one.

I bet they're gonna announce it in a direct with an anime to promove it.

or they can make a REALLY faithful FE4 remake in 2019.

also while metroid is a T, its way more mature than most M rated games.

Chuck 5 -10 million into an anime, translate it into Chinese.
Easy money.

Yeah, they could but it would honestly be easier to make a game from a genre that has both mainstream appeal and the ability to act as an entry point to many of the games that 3rd party developers make. 

Hopefully thats what Retro is working on(and other studios Nintendo owns).I would very much like to see how Nintendo tackles such games