Katie and Peter , Publicity stunt or genuine breakup?

I find the whole thing very confusing because they seemed so happy just weeks before with the London Marathon. But i can understand it being a publicity stunt because they both have big things coming out this year and they have recently relocated to America. But tbh i think even that is too extreme for these two - if it is a publicity stunt then they have gone way too far and it will backfire because people will end up losing interest in them.