Earlier quoted context omitted.
that would first of all take a lot of work to make it absolutely clear, a lot of work to use the mouse, and finally a lot of work to fight the lawsuits until it was established that you didn't violate and could do what you were doing. In short nobody but a crazy person or someone with a real deep artistic need that absolutely required that version of Mickey to work would ever pursue it.
It took one year from Winnie the Pooh entering the public domain to this: https://en.wikipedia.org/wiki/Winnie-the-Pooh:_Blood_and_Hon... And AFAIK they were not sued, despite being ever so slightly off brand for Disney.
I think as well Disney protection of its characters might be a more ingrained than just normal copyright protectionism - Walt was notoriously a bastard to anyone who messed around with not treating Mickey with the respect he deserved.