I wouldn’t jump to the conclusion that there was any kind of notice served to Canonical or the publisher.
Anyone who makes their snap private will show as 404, for whatever reason.
I think we’re best to wait for this to all shake down upstream, and then see what comes out of it. Having seen Github CEO Nat Friedman engage with the youtube-dl developers, I personally am somewhat confident this issue with be resolved at some point soon. Fingers crossed!
I’m not a lawyer, but speaking as someone who has had to deal with infringing applications.
We have some Terms of Service which I’d recommend reading. I’d recommend reading section 4 and 5 specifically which covers this.
We have had to remove a few applications from the store over the years for various reasons. We would rather not just roll over and remove things, if possible. But if there are genuine legal or moral reasons why we have to, then based in-part on advice from our internal legal department, we may well have to.
I can only think of a handful of occasions where this has happened.