Technologically speaking UA can do this... I had a situation a while back where I was already sitting in my seat in Business class w/ my boarding pass (This was an upgrade at the gate) on an intl flight out of SFO and a very rude gate agent came on the aircraft and made me get out of my seat, return to sit in coach to give my "C" seat to a late arrival. I was really upset but didn't want to get arrested or cause a delay of the flight co I complied.

And they pulled my SWU!

I eventually got a sympathetic ear from 1K customer service and they gave me an additional new SWU and extended the old expiring one into the next year.

So it CAN be done (despite one agent telling me it's not "possible" in the computer system).

Anyway, I'll wait till October and see what happens. Thanks everyone.