Yep. I haven't actually tried in the last year or more, but since they still retain the damage indicator bar, I assumed they still were. Just checked, and sure enough, they've changed it. Beacons are now as immobile and indestrucible as anything else. Sorry about that.
Now that they've given beacons an actual in-game purpose, I suppose I can see why they made this change; a beacon, once blown up, would stay blown up until the instance collapsed. In Open, you could grief the mission-runners without firing a shot, just by blowing up the beacon, forcing anyone else dropping into your instance to switch modes.
