So OBVIOUSLY WotC aren't going to sit on a literal money making machine and do nothing with it. So there will probably be a Baldur's Gate 4.

Larian have already made it very clear they want nothing to do with WotC in the future and are going off into the sunset to make their own games. (Good for them imo.)

So who do you want/think will take over for Baldur's Gate 4? There's some obvious possibilities such as BioWare who do technically have a connection to the old BG games. (Though none of the original devs still work there me thinks.

I don't think it's really a BAD idea to do a BG4 without Larian I just don't think WotC will give the new devs the time it needs to make such a complex game and worthy follow up.