XOR they'll just "conveniently" have copyright apply in court, even-though it doesn't apply on-paper.
Never believe a career-criminal, or Dark Triad entity, has changed, unless you see robust, consistent, years-long, actual, objective proof of that change having-happened.
They don't have to do any of those. They own most of the content pipe so anyone who wants to do their own spin on Mickey is going to be inherently limited on their publishing reach.
Plus with all the acquisitions they've made, the copyright to Mickey and other legacy characters is worth a much smaller portion of their empire.
I dont have kids so I can't speak to the ubiquity of Mickey Mouse - but was Mickey Mouse Funhouse or The Wonderful world of Mickey Mouse even that popular?
Frozen and Toy Story are their biggest sellers, it might not even be that bad for them to lose Mickey.