I'm not sure that it was Michelle not trusting it enough, just that commentators, probably even some viewers, and perhaps her coach, Frank (as suggested by a youtube poster), were not partial to the program. Thus, from some of the negative reactions, she was likely encouraged to drop it. I'm sure she trusted herself and her choreographer, Peter, but the unfortunate rushed timing of the program's debut and the negative reception may have convinced her to let it go -- she may have intended to revisit it, but never had the opportunity.
BTW 2000 Masters Rush sp (has problems loading on my computer tho')
http://www.youtube.com/watch?v=qlPvFn_vwBk