Effects of time changes is a bit maddening. Especially this episode.
I feel like no one put nearly enough emphasis on the impact of, the Doctor effectively murdering, and "taking over" the life of the "new timelines" Doctor.
Oh, so you are not my wife, and an alternate timeline version of her, who subsumed her body. Whelp guess, I get to seduce you again! Also, you just admitted to NOT being our Doctor, but ok, YOU still get to have top security clearance and be the boss.
I kindof think they should have went with the doubles route. ok, you are anchored and thus didn't get erased from time.. But now there are 2 of you.
The other thing with this new timeline. Humanity is around, if barely. Previously timeline, ok. Erasing this timeline, with a new one is "ok" because the number of survivor is so low. But the new timeline.. why do you continue? humanity is alive, and can rebuild.