To add to the above, if you actually got an e-mail and not just an "unread" message in the forum, that much you can control in your user Preferences:
I think this is the default setting, and it might not be what you mean, but it's an option some people might have turned on. Otherwise, a new "unread" count just seems to be normal Discourse (the forum software) behavior for many moderator actions, despite some feature requests in their forums for the opposite.
Since this was a one-time effort, as mentioned above, you shouldn't get this influx again [EDIT: OK, I guess a few-times effort spread out over a few days, so there may be a bit more]--but may see it from time to time on "Watched" topics in categories that are automatically closed or topics anywhere that are closed manually (often with a fun explanation from staff as to why -- or a real reply to go along with the unread count, at least!).