Honestly, I'd be surprised if every single person stuck around after such a long lapse in action. I'm sad to see 'em go, but I'd rather clarify that they won't be around than find out at a later point down the road.
Technically, yes. He could, but he just doesn't want to. If a reason crops up in the future that makes it clear that the groups need to fight to establish something, he may step in. For the most part, however, he's satisfied to sit back and watch how things progress on their own. That could easily change...
So say if two teams discovered a beautiful, lush island with all the resources they could possibly need to survive and the two considered sharing the island. Would the Maelstrom in turn be all like "Sorry, can't let ya do that. You two gotta fight for it. Go."?
Because the island would be gone within the next couple of days.
But in all seriousness, if the planet was stable enough to support something like that, and it remained in the same place permanently, he'd let them decide what to do with it. Whether they share it or whether they fight over it is up to them.