Even knowing the April Fool's origins I can't help but interpret it as a Discordian style satire of both copyright for trying to claim exclusivity and copyleft for going from undermining the previous to its own social contract. I am more than willing to admit that the idea may be from viewer preconceptions and overthinking as opposed to any inherent message beyond the inherently silly instructions.
I've heard of copyleft but I'm not too familiar it. Can you explain how it's evolved into its own social contract?
Copyleft puts the traditional concept of copyright on its head. "Copyright" limits "who can make copies." If I hold copyright on a work, only I can make copies (or only I can decide who else can make copies.)
Copyleft uses copyright law to enforce a different scheme, a social contract. The license, which can only be assigned by the holder of copyright on a work, insists that licensees (you, if you have access to my work which I've put under an appropriate license) must also allow copying by anyone, even when you modify my work.
I don't think this is an evolution, (the parent to your comment doesn't actually claim so); I think it was the entire original intent by Stallman. What has evolved is the terms of the GPL license, attempting to keep up with changes in technology.
"Don't say anything unless it's good. And this is good...(wink)"
--- some old TV show
This sort of reminds me of those copy pastes people would put on their Facebook walls claiming that they had no right to their photos. Are facts even license-able the same way a formula or code would be...
Wiki data has decided "no" to your question, all contributions are under CC0 (functionally WikiData only stores raw 'facts')
you can edit and delete comments with errors (within the allowed time)
Wiki data has decided "no" to your question, all contributions are under CC0
Is it just the Entertainment industry?
Does it mean that we can officially cancel social media?
It will work out like when Puritans canceled gossip and succeeding generations lacked it entirely.