All the major gaming news outlets praised the patch and how Karlach's gotten love. I don't think Larian will do anything anymore, they got their good press coverage just before PS5 release, and will make good sales. The ending they released is what they think Karlach deserves. There's nothing more to be done.
As for me, I've already given up playing. I cannot finish the game knowing what will happen. But I'm just one person, one sale. Larian will make so much money with this game that they have no incentive to care anymore. It's just business.
D:OS 2 was acclaimed, and Larian still gives a major update a year later for free, even if the game was 93 Metacritic score on first release. And it becomes the best-selling cRPG game ever with 7.5 millions copies. They're working on a major upgrade of their game engine, the game will probably be released on XBox considering the hype. They're plenty of reasons to think they'll continue working on BG3.
BUT. That's all in their hands. Or they choose the Peter Molyneux path, full of false promises, or they keep going on the CD Projekt post CP2077 release, with major improvement of their games related to gamer's feedback.
That's easy to make one good game and having the beginning of your game really good. But that's the deep base of player that makes your popularity. You cannot trick your deep base of players, espacially when you're Larian, that always go with crowdfunding and early access to develop their games.
Larian benefits from a huge fanbase of nostalgic players of old BG's/Neverwinter and a new generation of D&D players that wait for a decent new D&D videogame. That's why BG3 is so hyped. They can't allow themselves to just let it as is. Because if they just wait for the money to drop, their next game can be their last game. See how CD Projekt was at the CP2077 release. They could have just wait & see. But they work hard, and now there's a new hype for the DLC, and for the new The Witcher project. And now compare with Ubisoft that just over-use their licenses, how bad they're compared to their "golden era" after AC2. Larian know BG3 is not finished, not polished. They are a little ashamed of the ending and it shows in their communication "we know not everything expected is here pls don't be mad we do our best" style. That was the same thing with No Man's Sky and CP2077. Bruh I mean, only 5% of the players actually finish the game, 19% of the players just reach Baldur's Gate and only 36% have just finished the Act 1. Obviously a day or another people will start complaining about act 3.
We can only wait a year to see what they will do. If they do nothing, we are more than once to just never trust Larian anymore and wait huge sales to try their future games. Else, it will be a studio we can trust. Considering their past, we can be confident. But with all these actual broken promises about the end of the game (I'm not only talking about Karlach, but also the Upper City, the 17K ends etc.), it's wiser not to over hype.