Got some small changes to some late December flights, with times moving by 10-15 minutes to and from PVD.
Leaves me with a 41min connection in ORD for now!

41 mins, December and ORD ... what could go wrong ;) I would ask for different flights.

Seeing some very close-in changes trickle in for the next few weeks. The first EWR-PIT of the day (7am) is gone. And an ORD-LAX frequency got downgauged from 32Q to 320.

Does anyone have a clue whether the UA schedule for late December is now fixed and further schedule changes are unlikely?

A friend got hit with Thanksgiving schedule changes last week, so I think some changes for December flights are still possible.

My impression is that Thanksgiving + the first few days of December is done, but most of December is not.

the major December changes are done such as TATL trimming etc. I wouldn’t expect major things to come through anymore.

Got some nasty March schedule changes - 3 hours. Will need to cancel ticket :(

As did I but on award tix. 3+ hours changes on outbound, and inbound flight, they added an additional leg. No thanks. Called in, and agent asked "Which flights would you like?" Pulled up rev flights on UA metal and found something else decent. Miles price was more than double what I'd initially paid, but they didn't charge for anything, so I was definitely satisfied with that.

for me there is no sensible option on UA :( Better to get the refund and re-book OAL

Simple flying says 787 will start trips to LHR from EWR, "Chicago-based United Airlines will operate ten scheduled flights from Newark International Airport (EWR) to London Heathrow (LHR) during the second month of autumn. Ten flights translate into 2,570 seats offered in October 2024."

Do not see it in the schedule?

Yes. The flight number for the 787 EWR-LHR is UA 231, and operates Oct 16 to 25.

231 is the second (seasonal) daily LAX-LHR. I think the season for that flight is ending a bit before the IATA winter schedule starts on 10/25, but UA still needs to use that LHR slot until then.

Well, now I know why our EWR-CDG (UA57) in 3 weeks was changed from a 787 to a 767-400. This change did happen a couple of months ago but I'm still bitter about it :)
Or is this a normal change for fall/winter? This also triggered a departure time change to 20 minutes earlier than with the 777 this summer.

I think the EWR-CDG equipment change is independent of the 787 showing up on EWR-LHR for a week.