Has happened to me many times this year already. However, I have still been upgraded, often on the busy EWR-FLL/MIA routes (this being high season) where upgrades in the past have been nearly impossible to snag. Several things are at play here: plats paying a higher fare class than you and full Ys (as in the past); availability of B fares, which will put those customers into a F seat at booking (a new twist this year); and - in my experience, maybe not yours - weaker demand for F seats and fewer people paying higher fare classes, even with the availability of B, meaning that my upgrade chances have been at least as good if not in some cases better than they have been in the past. It's amazing to me that that I have been upgraded for EWR-MIA on a Thursday evening in late March, five days out, flying on a W fare no less.

In a couple of instances it has been instructive to be watching the pda site in the battlefield, sometimes after boarding, and see that several people either in F or at the top of the waitlist, actually do not show up -- getting me the upgrade when I had started out at 6 or 7th on the list - after F, Y, B and running of EUA. In this situation in the past, on these routes at these times, chances of upgrade would have been nil. IMO, this is the result of weaker travel demand, which makes me nervous for CO.

I have also had a few experiences where I snagged the B fare with upgrade when available, so CO is realizing more revenue from me than they have in the past.