I think the sales of Sen III will be key for Falcom's strategy. If the game manages to sell numbers that they are pleased with then I guess they will stick with the Ps4. If not, we might end up seeing some ps4/switch Falcom games in the future.
I see that Gust released 3 ds games. Did they not sell well ? I'm guessing that's the case since they haven't touched the 3ds since launch except for Rorona (which they went chibi style with...).