There's a disconnect here that I can't account for.
As it happens, I decided to turn in my LOTW credits (approved over night) and my current set of cards.
Between the two applications, I happened to have three XU QSOs on them, all approved.
As noted earlier, these were LOTW approved and sailed right through their process (overnight approval is fast even by LOTW only application standards):
27-Feb-2023 02:12:02 24912.4 FT8 XU7GNY XU
27-Feb-2023 02:40:33 28081.2 FT8 XU7GNY XU
and also this one on my paper application (the card checker, well-known to me, didn't bat an eye or warn me or do anything but treat it as another card):
21-Mar-2021 00:00:26 18084.0 CW XU7AKU XU
I suppose the card-checked QSO could still be canned when the application reaches Newington, but that hasn't happened in over 30 years of hamming. I would be very surprised, at this point, that I will lose any of these credits. Never had a "claw back" on any credit that got this far. And, I'm over 2450 on the DXCC Challenge.
These two LOTW ones are now part of my "approved" record.
OTOH, I do respect Tom's knowledge of these things. So, for now, I have to regard the whole thing as a bit of a mystery. WFWL, and turn in your stuff is my recommendation.
Here's a DX News article on the recent, just finished operation:
https://dxnews.com/xu7gny/Here's the DX News piece for XA7AKU:
https://www.dx-world.net/xu7aku-cambodia/I can't find any indication that these things are regarded as invalid, either by LOTW (where applicable) or by Clublog.
I even dredged up a third operation I worked for a Marathon point. Here's the DX News entry for that:
https://www.dx-world.net/xu7amg-cambodia/. . .still shows as "Cambodia" in Clublog. It was active in April 2020, just after Tom's stated deadline, but maybe in under that wire??
It's definitely a mystery.