It is a feature to help thread discussion between subs of the publisher and in turn the more subs that respond, the more likely the thread is viewed by non-subs. Most threads could use the added readership & who is more appropriate to provide feedback / spark conversation then their subscribers/fans. Ideally, in the longer term, this would help to bring subs of a particular creator together since you tend to converse on the same topics & presumably like what the creator is releasing elsewhere on the site.

Without this feature, subs only see when the thread is published and after that... even if it starts an engaging conversation, you won't know about it or have an opportunity to read the conversation or jump in. Even with this feature in place, a "bad" or resolved thread will fade when the responses do.

For PMC's account is was overwhelming because their posts appear in everyone's feed. When the feature went live, their old threads exploded! It quickly highlighted the issue you're describing. However, a cutoff was put in place.

It seems you have some active subscription threads that are reminding you of the PMC ones? I'll apply the cutoff on everyone's threads and see if that helps tip the balance towards cool instead of annoying. I thought it would be interesting to allow even old threads to remain alive among subs.