I posted about this earlier, and I do agree that if they are going down the commitment path - it should feel like a powerful narrative decision and not a "let's get rid of the inconvenient companions handwave" we had in DOS2.
Everyone that isn't in your party immediately dies to plot device #23 so that you can safely forget about them the entire playthrough? Feels like a bad design choice used to "improve replayability".
However, if characters you don't take are re-integrated into the story as proper NPCs - i.e. you leave Astarion behind and he's now a NPC in the Cazador quest line. Or Lae'zel joins up with the Githyanki hunting squads. Okay, I'm a little more open to that. Extra points if how they act as an NPC is influenced by your relationship while they were in your party.
Isn't that already happening?
You don't take Shadowheart = you confront her about the artifact and kill her and take it.
