Hi,
there s two ways to achieve your goals as there is no "unpublication" / "pause" process with Message Center
1- best solution:
filter out the eventType(s) that should not be process at the beginning
2- ugly solution:
create an eventType that is used by none of your templates (ex: "Fake"), assign this new eventType to all of the template that you want to "unpublish" and publish them:
All the upcoming events will fail as their eventType won't be able to find a template on the RT instance.