IRs have always been available to use with the KPA through Cab Maker, which converts regular IRs into the part of the profile labelled Cab. However, IRs under the new firmware will not be a necessity, as the new profiling ability will separate the cab from the amp, creating Cabs that aren't based on IRs or are an approximation of the cabinet part of the full profile. As time goes on and the new technique becomes more widespread, I envisage a new tag on the RE/RM that will distinguish pure, true Cab profiles (much like the Just Bass tag) from regular Studio Profiles, DI profiles and perhaps Cab profiles made from converting IRs. Being able to convert IRs to use as Cabs is just a courtesy on Kemper's part, in my opinion. I'm guessing that creating pure Cab profiles will prove to be superior than using Cab Maker to convert IRs to Cabs.
Cheers,
Sam