I agree with RetroGamer1224. Besides, the FTB team needs to spend time making the pack, getting permissions for all the mods, resolving ID issues, optimizing configs, etc. I don't think they want to start spending the time on making new packs unless they have to.
The other packs have a reason for being separate, as they aim to offer different play-styles or are based on the mods used by certain people / servers, not just "one mod didn't update."
There's also the slippery slope issue as I said before, if we do this for RP2 are we going to do it whenever a mod doesn't update? How big / important does a mod have to be to receive this treatment? How long should FTB give mod creators to update before pulling their stuff?
At least in response to that last question, I don't think we have given RP2 enough time, especially given the significant changes in 1.5.1 that affect many blocks in her mod (although I admit it'd be nice if she'd let people know where she's at with the update).