It wouldn’t surprise me at all if a Tuesday morning, 6:45 AM flight in early December from Orlando to Newark would be an upgrade opportunity for Silver members. (Incidentally, the flight was PZ2 when I checked, so UA was willing to confirm an instrument upgrade, which I rarely see three weeks out domestically).

We’re talking a leisure route, off-peak travel day, unpopular travel time, and off-peak season. A couple of weeks earlier or later, I’d probably agree, but the time between Thanksgiving and Christmas is relatively slow for Florida travel, especially northbound.

It’s certainly not something I’d count on, and I agree that I’d check for an attractive upgrade offer rather than expect the CPU to clear. But it’s not out of the question. When we see reports of Silvers clearing, it’s in these kind of situations.