Cue the incoming Charlotte comments, but this is a good idea 2 weeks out from their triple threat, and she should be on the show if she has the belt (the rest is another story...)
Not really sure who could take the mystery partner role, perhaps Dakota or Candice and they are two heels with the a fair bit of recent focus on them, but if there is to be a finish, rather than shenanigans then this person will likely eat the pin. Maybe Gonzalez would be a better bet? KLR would have been a great option in normal circumstances, but she's not able to travel.
They're putting a lot of effort into this show - cage match with Angle as ref, triple threat to determine who faces Fantasma (presumably at IYH), and then this featuring all 3 of the probable main event competitors at IYH.