Actually, I have an excuse (except for Taylor)
I did many more "matches" between songs than the ones I ended up using, and one of the them had my future. As for Ariana, there was a lot of work to do this, so to make sure I had everything ready by early december, I had to do it a long time ago. By the time positions came out I was already starting to prepare the video (this is the same reason why there's some late 2019 songs).
Very happy to see you liked it