Tom, BY738 has the answer re ABZ.

RYR 738s can fly out of ABZ happily presently, but as long as it’s to DUB (& soon LPL) & they are not filled so that they can take off from the runway!
Any destinations further away, they would need a longer runway.Hopefully that will be addressed by the time Oct comes around when LPL starts. RYR engines on their 738s are not as powerful as, say BAL (as was). Can recall BAL 738s flying to IBZ from ABZ non-stop.

Similarly, GSM 736s engines will not be powerful enough to take off from ABZ on its current runway length with a full load & fly to the destinations they want to (which I assume would be “bucket & spade” flights). Hence no announcements & no flights for 2006.