If you're in paid F that's a different story. Having a confirmed seat given away to someone else is a much bigger deal that an upgrade where you never had a F assignment not being processed correctly.
Agreed. And there have been stories of paid F seats being given away to upgrades when paid F pax is late (did not make the t-15 deadline) from a tight connection. This is unacceptable as GA is able to see if pax has a chance to make the connection or not, and should be waiting until the last possible moment to move pax (as in, hand the lead FA the new boarding pass to move someone up from coach right before closing the a/c door).