I would assume any depiction--named or just a visual--would violate the agreement. Hell, Rocket and Groot so iconic just an outline of the characters probably enough to trigger problems.
And social media is a thing. But TDO doesn't drop money on a dozen plus billboards and quarterly mailings and Stacey Aswad for charity--these are marketing tools in their toolbox. And even social media--if a blogger is getting freebies to talk about the WDW, there's a grey area there. I don't know that the Mouse wants to go down that road.