This simply shows that revenue management needs to do their job better than this. They did not C0 the flights with the intention of not letting FFs upgrade (if they were to do this, it would have been done long time ago). Their main goal is to force people to pay more for the 'J' booking class fares and FFs not being able to confirm their upgrades is a side effect from that. There are far better ways they could have done this and they better wake up soon.