Not sure why this wasn't advertised, but there's some new Planet Wisp stages. I just got Run 1, but there is a Run 2 and even a Battle one. Not currently in Stage Challenge, but you can see them in the Score menu in your profile page. Didn't see a round 2 Planet Wisp.

Run 1 was pretty fun, had a really nice remixed stage theme. There were some new mechanics in it. I think they should have advertised this as something new for season 3 instead of just saying what is new in the shop...!