I wouldn't be so sure that Easyjet has a huge love of Birmingham - perhaps more a case of trying to pick off the best routes from a weak Flybe that knows Virgin is unlikely to set up a major hub in Birmingham any time soon and there there is little synergy between the 2 airlines at BHX
If you see Easyjet opening routes from Birmingham to Aberdeen, Amsterdam and Paris, then you can be certain it's a case of trying to make life harder for Flybe