I'm surprised they didn't shut the Dumbo down as the issue potentially goes beyond a little scrapped fiberglass.
In warmer weather, stuff expands, and I would assume that the ride would have to have a couple of inches leeway, to deal with the expansion of the metal in the ride. So, as somebody said, is this a design issue or a construction issue. It could be one, or the either, or both. Somebody in design could have switched some number for the maximum width of the dumbo or something like that. The mistake isn't fractions of inches, but inches, that's kinda concerning. I'd figure that because the fiberglass shell of the Dumbo doesn't support most/any of the weight of the riders, a small cracked area isn't that bad, I doubt this relatively small amount of friction would damage the motor, but the effect on the tiles could potentially loosen them up.
The issue is what caused the problem, what if some of "nuts and bolts" connecting the Dumbos was improperly installed, and the Dumbos are slipping ever so slightly outwards with centrifugal force, (like how riders get pushed up against one side of the Dumbo).
This would be scary as potentially you're looking at an increased risk of catastrophic failure during operation. Dumbo ain't a toy, even though it looks nice, remember that the ride (or former ride) in Disneyland with the most fatalities was the relatively harmless looking People Mover.
If you like construction shows, then you'll probably get the reference when I say that the "Holmes on Homes" or "Holmes Inspection" guy should be called in to look at Dumbo. In typical Holmes fashion he'd look at it and find a multide of things wrong, and then head into the interactive queue and call up the owner and tell them that its worse than he thought and that the whole thing needs to be removed. His crew would take a crowbar to the McPlay area while he made comments like, "Who the heck does this? I bet they didn't pull any permits."