Think in this way: If Taylor only put 10 songs from 1989 on the setlist in May, then she played the 11th song here and there, after that she increased to 12

and eventually to 13 her lucky number.
Edit: I was JUST thinking about this: Did any major superstars put all their songs (Including bonus tracks) from the newest albums onto the setlist before?
Edit2: I think I might be the first member here, if not the only one, putting THIS LOVE as my number one from 1989 at the very beginning. It's still my number one 1989 song in my bedroom. But it really was not the best in my show at MetLife stadium.