Yes, I've seen similar ideas suggested before, but I think this is broken in many levels, for example: it's ugly, lacks flexibility, commoditizes relays and centralizes implementations, it's annoying for everybody involved, people can't change their minds after publishing.
Discussion
if the event is replaceable, they can change their mind. just replace with new rules.
it is still centralized in the sense you need to trust the relay to enforce this properly. I'm looking for ideas on how to implement this in a relay independent manner, completely decentralized. but couldn't figure out how yet.