I feel like even if they don't allow us to have a party of six, one thing I don't understand is giving the permanent boot to everyone else. The NPCs are a big component of these kinds of games. I know that these games came after BG/BG2, but Mass Effect and Dragon Age had the added benefits of your home base that allowed you to still keep up with certain companions and talk to them, developing their stories alongside yours. It seems like Larian already has that capability set up with the campsite. That's what I had assumed it was for, considering the way they utilize it in the game. It seems like a waste if they just make us throw all of those other companions away. My paladin of Torm may not necessarily like Shadowheart (once I can play him), but the idea that I could maybe get her to see the light would be a fun reason to keep her around, for example.
I get that it would take a little doing and that we don't know what the camp system may look like outside of the EA. But if it isn't changing drastically, it isn't as if Larian isn't already devoting the time and resources to having all of those NPCs available for plot development and the like already. It'd just be a matter of having them all present at the camp. Like they are now.
But also, yes, I'd love to have 6 people in the party at once. Hell, even just a fifth member would open things up a lot.