They're likely in contract negotiations right now. I looked at the timeline for DWTS in 2014 and Meryl and Charlie were unveiled as cast members on March 4, 2014, so the timing would be around right now for the Shibs, if they got it. With ABC also putting on the Oscars on Sunday this weekend, they might promote the cast this weekend with lots of commercials, or they'll wait until Monday or Tuesday next week to confirm the cast.
I also wouldn't be surprised if ABC leaned in with more skaters and potentially add Adam or Mirai to the cast. They'll already be attending so they might figure heavily in some of the pre-show events. My jaw would drop if ABC decides to cast, given the film on her life is up for a few major awards: Tonya Harding.
Sorry for the tangent, but let's watch their social media this weekend and see where the Shibs end up next.
Good sleuthing! I think you have this timeline nailed! Poor Adam and Mirai....they were hoping! If Alex and Maia are included I don't think DWTS will include additional skaters. They'd have to change thier names to Dancing with the Figure Skating Stars!