I would say that's made their return to CDF much more likely. Filing slots as we know is not a definitive yes but shows you're on the airlines radar
QR filed slots at BHX for S22 but never showed up, then again for S23 when they did. Slots were filed (I think) in Jan then official announcement for a July start made in March - so the timing of this slot filing for CWL fits time wise with how they did BHX.