...They probably aren't offering the IOM as a base yet because unlike virtually all other BACOn bases, nobody has offered their resignation there. The IOM base is nearly all crewed with ex-MANX crew, all happy and determined to remain there if possible. Add to that we also have a number of folk who are marooned in MAN or BHX as a result of the removal of the DH3 that was put there to replace the THREE ATPs we had and it adds up the the fact that there's a queue to get back.
I've been there 9 years, and with 6,000hrs and a long way up the ladder on the seniority list I'm still nowhere near the LHS seat there yet. One up from the bottom actually! If the plans to put a 145 there, then replace it with one or two DH4's comes to fruition, then I reckon they'll need 10-12 F/Os over the next two years for the Island, with possible commands coming for those who join first in about three years when the bulk of the current 146 skippers retire.
If you really want to join Flybe for the Island, either hang on or get a MAN base for now. Best of luck.