Skipness, can you provide a source that the Q400 fleet will be replaced by jets? Never heard of that before. My understanding is that the plan is to operate the Q400s and E75s alongside with each other, although the Q400s willbe reduced in size. IIRC, E75 delivieries have also been pushed back which does not really support the theory of a Q400 replacement. But I stand to be corrected.
As for BACF and LCY - with Cityjets further activities in doubt, the airport owners have a vital interest to attract new carriers to avoid a BACF monopoly at the airport. Should Cityjet disappear, the airport would be left with a dominant BACF plus just 10 routes served by 7 other airlines (3 of them by 2 airlines with a less than brilliant life expectancy).
By the way, interesting to note that the Flybe flights now appear on the official LCY website - with the exception of the EXT service. Which, IMHO, could suggest that EXT is just a slot holder for a service to NQY or JER.