I realize it's been three days (though we did have advance notice) but I've yet to see any uses of Steamboat Willie that rise above meme status. There's one joke - look, I made Mickey do something naughty! - and that's about all anyone has had to say so far.
There are public domain characters that do get used for real - Sherlock Holmes and Dracula are probably the biggest examples - but they each have a lot more lore and personality than Mickey. Seems like what this is really revealing is that Mickey Mouse was actually never a very interesting character on his own, and is only notable as a corporate symbol.
mickey is only an empty vessel for meaning. a trickster stripped of all malice and with any interesting edges sanded off. reduced to naught but three circles