Have they changed it? I haven't played EA, but iirc in the gameplay demos XP seemed to be the same regardless of party size.
No, they didn't change it yet, but that's precisely ONE area where they could easily address the problem as a whole. I'm fine with companions auto-leveling to keep even with you, but they could at least make that the number of party members decides how much exp each one gets. You know, precisely like in the old Baldur's Gate games.