I did NOT get the upgrade after all.

The RCC agent in Boston explained to me that my ticket was not "upgradeable" because the fare type was too low (U type).

I didn't think her info was accurate, and I tried to show her my
itinerary printout that shows the original (pre-equipment swap) upgrade
request was waitlisted and that it didn't make sense to me that the
web-site would let me request the upgrade if the fare was not eligible.

She told me that the printout didn't mean anything and that she was looking at the information (on her computer) and she was very absolute in her feedback that in her 30 years of doing this, a "U" fare is not upgrade eligible.

To make a long story short, dispite requesting the upgrade at the time of booking, and calling to confirm it was still waitlisted upon noticing the equipment change (early on day of travel), I was never actually on the list, I did not receive a DM card at check in, and when I inquired about it at the RCC, there was no attempt to correct the situation and put me on the list.
(I have concluded that somehow with the equipment chagne from a 757-200 to a 767-300, my upgrade request was dropped/lost).

I obviously have no way of knowing if my upgrade would have cleared or not, but I think that as a MP member (non status), I am supposed to be able to request a domestic upgrade on a "U" fare, and in this case the RCC agent did not help me with that request. I was given false information when she insisted that a "U" fare was not upgrade eligible...

Note that I am really trying to make a distinction between being able to request the upgrade and be on the wait-list and with the upgrade clearing.

If all the upgrades all went to 1K/1P passangers, I guess that is what I would expect, but I still don't understand why the RCC agent was so insistent on the non-upgrade eligibility of a domestic U fare... (I verified on the web-site that U fares are in fact eligible...)

The real challange for me is that I don't know how to respond to the "I've been doing this for 30 years, trust me, I know..." line when I kind of know that what I'm being told is not correct...