You guys are all missing the point. I don't care who is responsible, what the lawyers say, what Larian says, the expectation was created. This game was supposed to be 5e. That was what they caused players to expect.
That said, I love BG3. I'm going to still play it. I just think they're going to piss off a huge part of their fan base if they don't do some sort of authentic 5e rules difficulty setting like Solasta did.