On a recent trip my return flight was in the evening. I was tracking availability and status the day before, and EF showed All Economy 0 and All Business 7. No First on this sector. So it looked as if Economy might get overbooked, and I reckoned my chances at 50-50 for an OpUp with my Gold status.

Morning of travel, my Economy pre-booked seat number disappeared from MMB. So I figured demand must be huge for Economy and hopeless for Business - why else would they OpUp 12 hours before flight time.

I checked MMB again at T-3, and my original seat had reappeared, EF showed all Business 0 and Economy 1.

In the lounge or On board, no business seats were available for upgrade.

Now I get that one of two things happened.

1. Lots of last minute Business customers turned up, or
2. Several Economy cancellations and I didn't make the cut for an OpUp. But that is unlikely since Business went full and I did see few others trying to upgrade with miles in the lounge and told it was full.

Be that as it may, and airlines do work in mysterious ways. But isn't it unusual that my seat number disappeared at T-12? Why would they start processing OpUps so early?