i wouldn't say 'cruise past'. It will be a drive by speed at best.
It's going to be a close call in the next 5 years, but needless to say, Monarch issue aside for MAN and Ryanair at STN, both airports growing at a good rate, so I wouldn't be sitting there thinking it's going to be a dead cert like you seem to be. 'London' airport or not, both airports have their merits.
MAN has had a chunk taken out by Monarch, but It's made a dent, rather than be a catastrophe. The same couldn't be said about STN if Ryanair, Jet2 or Easyjet were to suddenly stop......