Well, I'd have liked more of a similar game, but it's hard to see how a full expansion would have worked. Extra missions in the middle would feel like you're being diverted away from the urgent issue of the Absolute, and there are so many potential storylines at the end from all of the different companions it's hard to know which you'd follow. And a new, bigger threat would cheapen the victory of the original game.
I'll keep an eye out for whatever they release next since I really enjoyed BG3, but I don't see any reason to buy early access. I'd rather wait for the finished game and experience the whole thing, rather than getting bits of the plot in advance, which is how I imagine early access worked in BG3
