I think the whole reason they went to his studio in the first place was not only because she needed to record some more songs but also because they needed a place for Joe to record the piano arrangement for Evermore (the song)? They were in London and she didn't have a home studio yet. Before that part of evermore (the album) had already been recorded at Long PondThis has me really hoping Taylor and Marcus collab again. I love his most recent solo album (I wouldn't be surprised if they worked on something for it that didn't make the cut, since it was kind of random she went to his studio and everything just for him to sing some background vocals) and I think their voices go together so well.
I love that she always brings out special guests.
I wonder if because of the length of the show if there will be as many this tour as usual though.