I would have thought that Stobart Air has achieved its main objective which was to attract attention to SEN and entice big LCC's.
Surely now Stobart Air would be better to focus entirely on the Aer Lingus work they are doing for fear of losing that to CityJet in the future? Especially given the added annoyance of having to gain a UK AOC by March 2019 - for what?
However Stobart have been known to be completely unpredictable and irrational - so who knows!