Also should be pointed out, publishers don't publish games to 'break even' or 'make a little profit'. They want to make the moolah. And, they certainly don't want to wait 5-10 years when the game is in the bargain bin to see a return. L0L
As for BG3, it'll sell. Too many factors in its favor. BG's legendary status, Larian';s own reputation, 5e dnd's popularity, the supra hype and media fawning, etc., etc.
Selling the game won't be the issue. Making a sizeable enough profit to make the investiment worthwhile is the key.
Have little doubt it'll make some profit but the key is how much and how much needed to make the time, # of employees, and everything else worth it to Larian and WOTC.
As far as I understand Larian are completely independent, and they fully funded the development of BG3 on their own so WotC have no financial stakes in this game. They might get some royalties from sales because they own the IP but they don't control Larian's future. Also important to notice is Swen literally said just a few days ago that WotC are VERY happy with how BG3 turned out. On top of that WotC also don't really have any alternatives really...BG3 is easily and by far the most popular D&D game ever made and will easily and by far sell the most copies. They don't have room to complain that oh this only made 5x the dev budget when we wanted 25x or whatever because they don't have anyone who can do that and nobody has even come close to doing as much with the D&D IP in videogames as Larian has with BG3. So I wouldn't worry about WotC acting like a big bad publisher, they don't have that kind of leverage here and they don't have better options.