Originally Posted by
skybluesea
Had PY IRROPS and only space available was J - two seats provided DUB-LHR-YYZ-YVR, with first leg in biz on Aer Lingus too.
But that's a different issue. No space in economy/PY.
The OP is talking about rebooking in booking code Y when there may well be inventory in the original booking class.
And then, not sure if it has been mentioned, there are cases of rebooking in a lower booking class than the original one too.
Finally, there is rebooking in J/C/D/Z when the original ticket was an upgrade. Some years back, even helped my gettinh aver the 100k requirement.