I know you can’t announce you have someone on ignore outside the Pit. Does that also hold for threads, since it could cast aspersions on the thread starter? I’ve been nuking them at an increasing rate, typically just silly threads or rants about topics I don’t care about that I keep seeing on the sidebar.
What would be the context in which you’d mention it?
“Ugh, I just muted yet another thread from CaptainAnnoying” would probably be bad.
“I have no interest in threads about the migratory patterns of European birds, so I muted that thread” would probably be OK.
I’m kind of curious why one would want to mention anywhere a thread they weren’t interested in. You’re basically asking if it’s okay to thread shit as long as it’s not in the thread you are shitting on.
You have to be very careful to not insult the poster in question. Basically if you feel the need to talk about it try the What were you THINKING? thread. There is little reason to bring it up that I can think of.
Prior similar ruling:
I can give a couple of examples of where I’ve muted threads and categories, and brought them up without getting in trouble. (And in giving those examples, I’m doing it again!)
I just don’t care for the Thread Games category. I don’t mind that they exist, and I am glad folks enjoy them but in my case they are just unnecessary clutter so I have the whole thing muted. For me it doesn’t exist. It’s no insult to anyone, it’s just not my thing.
Similarly, someone was creating threads in Cafe Society that were talking about songs that begin with a certain letter. There were a lot of threads, pretty much one for every letter of the alphabet. Frankly, it was extremely annoying, just the sheer volume of them, and I even objected to them being in that category because it seemed more like a “Thread Games” topic than anything else. I think I even reported one of the threads to complain. But a mod (probably WE? who is freaking awesome) made a custom tag for them, and all I had to do is mute the tag, and they all went away. Again, nothing against the poster who made them (and I don’t even remember who it was, I don’t think I even paid attention to who it was), just not my thing.
The only times I brought them up as examples, though, I think have been here in ATMB. And I did so specifically to talk about why tags are so useful, and also to talk about how effective it is to mute a category you have no interest in. Well, until just now, when I’ve brought them up again. 
Good examples where used neutrally.
Thank you for the compliment. And yes, I made the special tag and in an ATMB explained how to use it.