The idea of the protest is to either forcibly reduce user interaction/retention on the site or raise awareness of the problems that the API changes will raise, spamming John Oliver in pirate clothing won't effectively achieve either.

I like the idea of r/theyknew which forces every post to have an image saying that reddit is killing 3rd party apps. But even that would be better in bigger subreddits which constantly gets r/all coverage.

The way r/piracy is "protesting", it's better to open away, it's not like Reddit wants copyright circumvention to be discussed in their website.