Personally, I was never so disappointed in a game as when I discovered half of my party was gone in DOS2. Just like that.
Even if I'm going to replay the game no matter what, I find really annoying to cut half of your party just to "force" you to replay. Maybe I have not the time to play an 80+ hours game more than once or maybe I just like to explore the personal quest of all my companions with the same character.
I understand that Larian can't please everyone, so my preferences are inconsequential. At least I hope they are going to make the separation from half of your party sensible and credible, not like in DOS2.

For example, in the first Mass Effect, you need to choose between Kaidan and Ashley. It breaks my heart every single time but at least is a good scene, not just a message "You are changing zone, are you sure you want to keep this party? You may not be able to change it for a while".