Are EUA's typically protected?

The few times I've been EUA's and volunteered to either be bumped or standby for an earlier flight, they would always put me in F class on that other flight.

I was recently bumped on a LAX-EWR flight in Q class that I was EUA'd on and rebooked in F on a later flight.

I'd assume once the F boarding pass is issued, CO must provide you with an F seat. (Then again, I've learned from this board that nothing can be assumed from CO.)