From the larian writer who was streaming:
there will be at least eight companions, possibly some who aren't origin characters.
evil route definitely needs more work, currently feels too much like a cartoon villain
playing as a custom character felt underwhelming in DoS2, don't want it to happen again in BG3
Kagha is going to see heavy rewriting(in line in with the above evil route rewrite, I assume), feels too one dimensional.
EA is definitely not all of act 1, moonrise towers are part of act 1 <- this one is kind of interesting, the EA is already pretty big.
if lae'zal dies on the ship you find her corpse on the beach, you're meant to be able to resurrect her but it's currently not in