I dunno, if you want to do that it would actually be better to just send that clear message in a more direct manner -- GitHub just doesn't have good tools around this yet. Until better tooling gets here, maybe it makes sense to just very quickly ban pests, and make it clear that pests won't be tolerated?

Also I want to point out that I'm totally fine with quickly closing tickets with no reproduction details or without enough information. Bad tickets should get closed if they're bad, especially if there's a template in place that the person has ignored. I would say that if 10 tickets from different people are getting filed from a specific area it may be worth looking at even if all the tickets are badly specified. In general a closed ticket with an explanation is so much more valuable over time than the alternative.