Yeah, can't be J->F upgrades; in addition to Stripe's solid points, I'll add that if they cleared 8 J->F upgrades that would free up 8 J seats, which would result in 2-9 on the list clearing (assuming those were Y/W->J requests). If they only cleared 1 Y->J upgrade, they didn't clear more than 1 J->F upgrade.

I have no idea how Y->W upgrades work, but maybe that's what's going on? Seems odd there would be 8 open W seats too though. I don't have any other theory, but I find it pretty unlikely that they just straight skipped 18 people for no reason.