Game Freak has made several other non-pokemon games, 2021 is the 25th anniversary and the new anime will probably start airing in 2020 so it'll be used to promote whatever they're doing for the anniversary, 3ds isn't totally dead yet so technically the sinnoh games are playable on current hardware so remakes will either be next year's game since swsh will have increased the pokemon fanbase's switch ownership rates, and as much as the dex cuts suck they specifically said they plan to continue with the new policy moving forward which means they intend to keep the main series going. The only question is whether they get enough of a smack to start putting in real effort and care like other game dev studios or if they just keep everything on life support so they can rake in the money from pure brand recognition.