So I got some good insider news on this tonight... Sounding like this set is 100% new. there was some speculation it wasn't since the bike on the Vintage AT-AT box is clearly not new, but I've caught wind that the new one is wholely separate and the AT-AT's bike is because the mold for it is with the molds for the AT-AT. No more, no less.
So from what I gathered, a 100% new tooled, new scaled bike is here it would seem.