It's getting more complicated.
I have all the documents needed (vaccination and insurance) for entry into Thailand since they don't require a Covid test.

I'll only be staying for a few days, though, then I'm moving on to Canada.
Technically I'm not transiting in Bangkok, so there's no connecting flight, but Canada will still want the covid test (in English or French) because I've been in China within 10 days.

Thanks Fabey.
At this point I think I'm inclined to get the covid test even if I may not need it.

For Thai entry I've already got my vaccination certificates and health insurance ready.

My only concern at this moment, then, is that I have no idea where I can get a covid test.

It seems like most of the community testing centers are shut down and hospitals are restricting testing to inpatients.

Thanks Fabey.
Where was this announced?

As usual it seems the only notification I receive is from GoKunming forums. Airline and travel agent have not given any notification and browsing the web just in the past hour yields nothing from Thailand either.

The change in arrival is confirmed by a story on CNN this morning. I notice that even though there is no quarantine, it may still be necessary to have a negative covid test:
"Travelers still must take a Covid test before arriving in China, but passengers will no longer need to submit their results to a Chinese embassy or consulate and apply for a code. Starting January 8, travelers can test and display the result before they board the plane."

edition.cnn.com/[...]

I'm interested in the answer to Kelisi's question, but since I'll be going out in January and returning in late February or early March the rules may have changed a dozen times between now and then.