Alia is a tough character to film, not many child actors that can pull that off, so the choice to keep her in the womb is one I'm okay with. As a consolation, they do show her in Paul's future visions, which is a power of Alia's you only see with her and no other prescient in the series--the ability to leave future memories and messages for another oracle.
One line of concern from part 2 is Reverend Mother Mohiam's admission to Irulan that the BG were behind the Atreides destruction, not the Emperor. It conflicts with Mohiam's ask in part 1 to the Baron that Jessica and Paul be spared. I think the writers for the films added Mohiam's line in part 1 to balance Yueh's role being downplayed (since he largely saved Jessica and Paul), then added the line in part 2 to match the expanding role of the BG as the antagonist, and missed it on further passes to see if the characters' goals still aligned.
I greatly enjoyed part 2, I like what they did with Irulan, Feyd, and Chani. Looking forward to reading the discussions and bringing new fans into the series!