AA knows how many people are waitlisted for SWU upgarde. And they have been prioritizing (unadvertised) people in PE over Y eventhough rank is otherwise. So they can oversell PE - they will likely drop 2 seats out of J inventory (hold back) to be sure they can process the SWU.

I have seen this domestically - like 1 F seat left and Y is sold out - so they go 1F 1Y - which ever sells first they pull the other. If high cost Y sells, they know they can upgrade an Elite from Y.

Only problem here is you may have trouble gettting 2 seats together after they clear the upgrades.