I get that having a full roster of high powered adventurers sitting around camp-keeping due to artificial party sizes is a common issue in RPGs, and I don't think forcing the players to commit to a party is necessarily bad. However, it really depends on how it's implemented.
If "commitment" leads to the people not in the party conveniently being erased from the story by a plot meteor swarm just so it enforces "replayability", then I would really prefer Larian just leaving them as mindless slaves in my camp that I bring into the party occasionally to do their related quest (i.e. like in most other RPGs).
If "commitment" serves a deeper purpose to create immersion - i.e. implemented in a smart, reactive way to really liven up the world, then I'm all down for it. For example - say you don't commit to Shadowheart. Instead of just being erased from the story, Shadowheart now continues on her own quest/goals, and later on, becomes a proper NPC either in a Shar related quest or if you ever visit the stronghold. Depending on your previous approval level, she might be straight-out hostile, a reluctant frenemy - or even an ally or can re-join your party temporarily (maybe after some convincing and apologizing). I.e. give them the Witcher 3 treatment and make them NPCs that are deeply integrated with the plot where appropriate. This - I'm all down for.
