had to release Steamboat Willy into public domain.
Not even remotely comparable.
Code isnt something publicly accessible in the first place. You cant force a company to make a private thing become public, and I mean that in the literal sense of "this wasn't something outside people could even see"
Because, to do so, you'd have to first force the company to keep their internal copy of it archived, which you also can't force them to do.
If a few years later you go "You have to publish this source code now" and the company goes "We don't even have that around anymore, it doesnt exist" wtf are you gonna do about it? It's been deleted, and it was never publicly accessible in the first place, so you have no idea what it even was or looked like.
As a result, you can't force anything about it, it literally doesnt even exist anymore, so you can't travel back in time and make the company undo that.