Let me say two things right off -- the first is that I just picked up Fantasy Grounds Unity over the weekend as part of a bundle -- OK< and most of the bundfle -- and the supporting material I got is for PF1, not PF2. The second is that I am aware of how hard a difficult work it is to add a game, even a subgame, to the FGU catalog.
That said, I can;t help but think some of the items I have in my collection (which is much wider in scope electronically than on my shelves -- the only Paizo core book there is Starfinder). That said, there are some really ewxciting PF subgames like Ponyfinder and Pugmire, that hole considerable appeal as a GM or even as a player.
So how many people in RPG fandom would be at all interested in these games, as a general rule (I'm not soliciting for players, at least not until I've got all my dogs, cats, and magical horses in a row). More to the point, who uses Fantasy Grounds?