Most if not all are now required to use ART. Candy Cane was Grandfathered in. My understanding (and I could be wrong) is that if they were to make ANY changes (renovations) they would no longer be allowed to have their own and would need to use ART.
In all honesty, if I was staying at CCI I would walk to the park vs the shuttle.
DoubleTree, Courtyard Anaheim, Cortona Inn, Sheraton Park....those are a few that I found when I checked Google maps. If you type in "Toy Story Parking Lot" it'll bring it up. There's a lot of hotels around that area. We stayed at DoubleTree last Oct but didn't use the lot, if we stay there again I think we'd try that out vs ART or walking.