UNLESS there's a medical reason for it, you should be able to walk in and get the vaccine. I KNOW in Kanchanburi they are giving it out for free at Robinson, TMK, and Big-C without any ID required. I'm sure it's similar elsewhere too.
I already gave you the official news, direct from the source. You can either reject it because it's not published in a online newspaper, or you can believe it.
That is *NOT* The official newspaper of Thailand. That newspaper does not define or publish the laws. The Royal Gazette is the newspaper of record; all laws, rules, and regulations are published there.
The Bangkok Post is *USUALLY* a good source for secondary news.
The Thigar is a good news source for very local news, but bad for repeating anything that's been published in the Royal Gazette.
Source on the meeting? I have the Royal Gazette up on my computer, and there's been no changes to the NEW 60 day extension of stay based on unable to travel due to COVID-19.