It pays to be diligent....
My girlfriend and I flew home to CT this past weekend with some friends and when I booked our return, I purposely put us through EWR to connect with CO63 (a DC-10). Before I left on Friday, the A inventory on CO63 was about 20 according to ITN (0F). Well, come EUA time, the A inventory was down to four! So I kept checking my email to no avail...no upgrade.
So when I thought I'd let it go, I checked around 12:30AM on day of departure and there was one A/F left. Thankfully, I called and was able to score "the last seat in first class". OK, more incentive to get to BDL early. That paid off as luckily, my gf was one of two upgraded before they closed the door out of EWR! Don't worry, the other couple left the day before.
Moral-is it possible to rely on the EUA?