Personally, what I think GF should do in the event their games' sales begin to dwindle is one of two options. Option number 1: they focus on making the mainline Pokemon games extremely robust, filled to the brim with hundreds of hours of content, high production values, good graphics, introduce complex new gameplay mechanics while keeping the old completely intact, and of course include a full, uncut national dex. This in undoubtedly the most financially expensive and time consuming option. Option number 2: they greatly expand upon the sexual titilation aspects of the mainline games and transform Pokemon into something similar to more recent iterations of the Persona or Fire Emblem series, wherein cultivation of romantic relationships with NPCs and even your Pokemon become a central focus. The overall game structure remains unmistakably "Pokemon" with regional traversal, gym badges, league challenge, evil team, etc, but these new relationship mechanics are introduced and eventually fully woven into the core experience after a few generations of tinkering with the formula. This is the most "risky" option. I'm sure turning a once "E" for Everyone game franchise into a "T" or even "M" rated series would be quite frightening for GF/TPC. After all, their actions thus far seem to suggest a substantive fear of being perceived as anything but a company that makes games for toddlers. But in a world where little Timmy is more likely to ask his mom for Call of Duty, FNAF, or Fortnite as opposed to things he sees as "babyish" and beneath him, like Mario or Pokemon it really isn't much of a stretch. Not to mention Nintendo's current stance on sexual titilation in 3rd party games on their current platform, the Switch, paves the way for a much rosier future for 1st and 2nd party Nintendo exclusives as well.