Astarion remained pretty similar. The biggest changes were to his outfit and face, though he was still instantly recognisable as the same noble high elf with his pale skin and silver hair.
Here's the situation: it's possible that, after you long-rest multiple times in Act 3, vampire spawn will ambush your camp with the hope of returning Astarion to his sadistic master Cazador.
Astarion from Baldur's Gate 3 was originally a Tiefling, not the High-Elf fans know today, with yellow eyes and dark hair. Game developers ... With how long Baldur's Gate 3 has been in development ...