I'm guessing there is more to theinvestigation and others have been watched for some time now
One would hope so. I believe the spooks call it "walking the dog" (whilst paying close attention to the assholes it's sniffing).
And how exactly does that change a thing?
Me? I am pleased to know that something was being done to root out traitors. "When" is irrelevant, so long as it's not "after the (horrible) fact".