Can't say I envy anyone who has to follow after Larian's footsteps.
But as far as potential devs that fit the bill…
BioWare couldn't do it even if they wanted; the version of the studio is long gone. And obviously they're busy with both Dragon Age and Mass Effect.
There's Spiders, but I don't know if they could pull off something as big as BG3.
Obsidian has been done with doing licensed games for a while now. I doubt they'd be interested.
There's inXile, but, like with Spiders, I'm not sure they could do anything close to the scope of BG3.
And on top of all of this, would MS even be okay with doing another licensed game? Yes they're working on Blade, but there's a bigger incentive to work with Disney than there is with Hasbro/WotC.
I don't think anyone needs to worry about Microsoft making this game exclusive. Microsoft is very clearly moving away from that mentality especially for properties like this.
Yes but would that agree to day one PS5 and Switch 2 versions? Not this whole "indeterminate timeframe after launch" stuff they're doing with other games.