The trip to Baldur's Gate takes like two weeks going around the Shadowlands right? Going through isn't exactly a lot faster due to the circumstances you run into there. Then Baldur's Gate is however long that can take after that. I don't think they ever intended for a baby to fully be around like in BG2. I read the lines as more of an early realization and whoever was commenting on it sort of mulling over what that means given the current chaotic situation. I think involving Orin so centrally in that is asking for a big mess other than maybe reactivity where she gets nostalgic or jealous over it or something. But otherwise yeah there's sort of a LOT of unexplored depth to Minthara's situation with Menzoberranzan and her family that would be so interesting to see more thoroughly discussed as she goes through her character development, and how the idea of having her own child would settle in with the rest of her thoughts. Still that's really easy to mess up so I don't blame them if that's what got cut (but I can't imagine it was anything else).