My theory:
The aim is to promote the tour, because that is where the money comes in.
And with the tour announced, every single, video and album release is indirectly promoting the tour.
Also people don't have to wait for the tour to be announced and can instantly buy tickets.

My guess: 1st single: February/March – album: April/May (Although for an album titled 2020 May seems to me already a bit late.)