You should be able to subscribe to just that Major Incident on the Status Page and not the Service itself. You should be able to then advise whether you would like updates any time the Major Incident is updated or just be advised when it has been resolved.
There should also be a button to select that I am affected by this major incident as well / be able to create and link a child ticket to the major incident. This would help with reporting as to how many people were affected and also be good customer service.

