My brother also posited Susan, but earlier in the episode. I think I'm growing to like it, though it requires a bit more work to understand how Susan got into Time Lord government than to say she's Romana. I'll ask him later what he finally decides on the matter.

That's even creepier than genocide.

Pretty sure it's not the first time I've suspected this either, though I can't recall what first led me to think about it. Maybe because I find the Doctor/show implying that the Time Lords were preventing alternate timelines involving THEMSELVES to be the ultimate in creepy. I would want to get the fuck away from any people like that as well.

If true, it would be an equally horrific comeuppance for them.