Sorry. I did not mean to imply that I would be disrespectful to a gate agent or indeed anyone working the front lines at United! Simply that, as discussed above, the GA often needs to call a help desk anyway, or the supervisor or another agent next door to figure something out.
All I want to know is, if I have a Z fare ticket, I am entitled to a rebooking into another business class seat if a flight is cancelled, ie goes mx, as noted in the original post.

I appreciate all your insights into the workings of the ground staff at UA!