Another big reason (perhaps the main one) why Sarah refused to appear at past CPACs: Sarah had a huge dispute with ACU head David Keene. He insulted Sarah, but now I can't remember the details. Keene retired at the end of last year's CPAC; Al Cardenas is the new ACU head honcho.
I hope you're right about GOProud getting the boot - they had NO place at CPAC IMO.