It makes every sense to get rid of the younger aircraft as they are different in many ways in the cabin and it removes the fleet a whole year sooner if Flybe decide to replace the Dashes en masse.
What would also make sense is re-leasing some of the very old G-JED#s to fill the spaces in handbacks made by selling the owned hulls and also to fill in later gaps in deliveries that occurred as they got them in batches.
Handing back the next in line as the E175s arrive could well see the fleet handback process condensed from the 10 years spread in deliveries to less than 5 years. if it works it might well play into the compnay's hands as manfacturers work to provide a suitable replacement for the short sector workhorses.
Bring on the lightweight E170s with geared turbofans! Please....