In the old days it was easy to unsubscribe from Apple Community Support emails. Every email had an unsubscribe link.
That's the right way to do it.
Somehow, that got forgotten when Apple made their support community "Social". I'm getting emails from every thread I've commented on, and I couldn't see how to stop them.
This stuff isn't hard, but Apple blows it every time. Something about their culture.
Anyway, this page seems to be the trick. It was a bit hard to find:
It lists all the items I'm (unwittingly) "watching". I clicked each one and removed it. You might be able to find it in in Apple Support Communities> People.