I tested the difference in my own waitlist order with this test, but the confirming experience happened today with a colleague, XXX-EWR. Colleague is a 1K, I’m a GS. Colleague was booked in R, Premium Plus, and I was booked in B, Full Fare Economy. I ended up #3 on the list, and he was #1. Another PP customer was #2.

Here’s the current language from the website, and this does appear to be a change, or a glitch. I cannot see any language any more stating GS in any class are cleared to Business before any other members:

* On flights equipped with United Premium Plus, we will process requests to upgrade to business class for customers ticketed in United Premium Plus (fare classes O, A, R) before processing requests for customers ticketed in economy.

Upgrade priority on United Premium Plus

On aircraft with United Premium Plus, we’ll first process United Polaris business class or United Business waitlists for all members who have purchased United Premium Plus seats, using the same priority order that applies to all upgrades. We’ll then process waitlists for members with United Economy seats.

Did your colleague use 1K PlusPoints ?

I don't believe there ever was language stating such; it's just how we observed things working in practice.

And for what it's worth, as far as I can tell, PN any cabin is still being ranked above PZ any cabin on the waitlist. So I also wonder if your 1K colleague was having GS +P, as asked above? I suspect the report of a gate agent saying, 'not eligible' was a fluke / I-know-better agent.

For the TPAC market I fly most, typical RT P/D fares are $5000-$6000, Savers award 70K miles one-way. More like buy one get second one at 50%.

Regarding the one-leg companion upgrade: Does it work when you're on different itineraries, but share the same final leg? Could the upgrade be used on that final leg?
Example:
GS: ORD - LHR - ORD (J)
Non-GS: SFO - LHR - ORD (V)

Could the companion upgrade be used on LHR-ORD?

Yes you can do this -- I did this for my spouse returning from Japan - but we got there differently...

If you are on the same flight, you can request an upgrade for the companion. It is different from being on the same PNR. If on separate PNR, you can not request in advance, but at the gate and the companion's waitlist will be at the bottom of your status group -- essentially as if a $0 fare.

So, you physically approach the gate agent and request the upgrade? Or can you call someone like the GS desk to pass the request to the GA? I worry about a long line at the gate.

Gate agents can certainly add your companion to the list. If you're at a station that has a GS reception, you can also ask the GS agents there to add them to the list.
Nowadays most airports have the new "virtual customer service" feature where you scan the QR code to chat with an agent. As long as they connect your to an agent physically working at THAT airport, they should be able to also add your companion to the upgrade list.

The GS desk (or any reservations line for that mater) wont be able to add. You'll be told that the flight is "controlled by the gate" within 24hr of dep.

Would this GA procedure apply, since the upgrade in question refers to the LHR-ORD?
Seems this would be an instrument-supported u/g, which can be requested ahead thru GS desk.

Thanks. I know GS lobby at SFO can call gate, I also had HNL UC desk call gate, but did not know about the virtual customer service. Where are they usually located?

So yesterday I was using the app to show a friend (UA Silver) that I could not use my Plus Points to upgrade his Y flight booked with his miles, because it only works if the award ticket comes from another GS account. But it worked (he's waitlisted at #1)!

A glitch, a change in the rules, or my misunderstanding of the rules?

As others have said, yes the companion upgrade works on a specific leg as long as you're both on that leg. If you're referring to the benefit when you buy Polaris and use PlusPoints to force upgrade a companion's segment into Polaris from economy then you simply call the GS line and have them confirm the upgrade immediately (assuming all requirements for the exception are met).

This sounds like a CPU situation? Not the scenario outlined above where CPU's wouldn't even apply.
You certainly do request the companion upgrade in advance when you're flying business and want to upgrade a segment of your companion's itinerary and wouldn't need to deal with a waitlist nor wait until at the airport as that's the whole benefit of the upgrade perk.

New one
 

Has anyone ever had an agent refuse to push through an upgrade on plus points at T-72 because another segment on the itinerary has already cleared (normally)? This is a new one for me and agent swears she is a real gs agent.

I haven't gotten that exactly. Several times, I've gotten: "We forced once segment to clear when you booked, therefore we can't push any other segment through at T-72" I think others have mentioned this above.

Your experience is a new development. I guess they just keep tightening the noose. I recently hit 2 million miles. I may not go for 3 million because of this crap.

I recently booked a trip to Africa on United & Ethiopian with $4K in cash and 130,000 miles. Then realized that I could have flown in Qatar Q-suites for only $4500. Polaris is to Q-Suites what AMC Pacer is to Lamborghini. I'm not sure it's worth making that kind of sacrifice anymore for the ever-declining elite benefits on United..