Larian set the expectation themselves with dos2.
A definitive edition with reworked 3rd act.

And of course people are disappointed when Larian does not deliver that, despite BG3 being in a worse state than Dos2 and it being such a massive success.

Also, long term support and definitive editions for RPGs are more or less industry standard by now.

The Pathfinder games got them and still receive updates even outside of DLCs like the devil improvements last month.

Cyberpunk got massive support before the DLC.

Disco Elysium got voiceover and new content in its free Final Cut update.

Compared to that, Larian didn't do much for BG3 before abandoning it.