I believe the CE issue prevents them from further litigation (1325). The fact this was not appealed in 1321 creates issue preclusion.
World's cannot simply throw darts at the wall, hoping something sticks.
In your opinion "The burden is on Bungie to prove they are not an RPI to Activision". I simply disagree.
IMO I agree with the brief: "Worlds permitted the final IPRs to become preclusive with respect to matters actually litigated therein. This includes RPI"
Understandably, we have differed opinions. Will be interesting to see this play out :)