This one seems to lie in the lap of the TP organizers, not Palin’s team. There’s only so much control you and your campaign team can have and about all you can do in that situation is pull out. I think they were going that way because as the WaPo article stated there were a number of changes happening right before the gig, and the Palin team was feeling like they were on quicksand. It happens alot.
Nice little indirect observation though, this tempest in a teacup does make it look like she’s in for the win.