Well, I would say Steve is about "as in the know" as you can get since this is his site. :lol:
But, logically, it makes sense that M:S needed to test run a lot earlier in advance because it is new technology. Philharmagic should not need much preview time, other than for the purpose of training and to make sure everyything is running correctly. I doubt there will be much, if any testing prior to the AP previews.