Unfortunately Thomsonfly is no longer the 'career' airline that might have been the case with Britannia. Quite a few experienced, but low seniority FOs are leaving. My base has 2 Capts and 2 FOs on notice to leave.
If someone else can offer either a DEC or quick command then people may well take it. Recent moves have been to Emirates, Ryanair, GSM[?] and Corporate.