This already happens with paid relays. It’s different from Twitter because you don’t have a choice over there, but you do over here in regards to which relays you want to use. What he’s suggesting is adding extra information so that clients and relays are smarter and don’t waste resources attempting to connect.
Discussion
Yes, clients and relays will something like a blacklist or blackmark to prejudge a user and don't service it.
And not everyone can run a relay for himself.
I prefer to block spam bots manually, rather than having facilities for blocking systematicaly.
Just my dime.