If by "New Rules" you are referring to the new Covid Restrictions, they would only be applied upon entry. You are already in Thailand, so not an issue. And, simple and easy to get 30-day Extension with TM7 Form, and your local Immig. Office, and 1900 Baht.
Thanks "Mate" for your Opinion. I'll Treasure it Always. And "sincerely" apologize -- Not -- for my attempts to provide accurate information (or in this case, note the IN-accuracy of informtion provided by others) for folks trying to make Travel Plans.
Actually, all I have been saying (and re-posting everywhere), is exactly that: Let's wait for the "Official" Govt. Announcement. Not trying to "take over any debate". Trying to settle everyone down, and stop providing advice based on UN-Official info. (And, FYI -- Not just Judge "past". I am a current and long-standing appointed Arbitrator Judge for the Thailand National Arbitration Commission (along with similar appointments for more than a dozen other Countries).
We appear to agree on many Posts, but this is not one of them. Indeed, you did not identify the source of the "Notice" you posted (or where you got it from). It appears to me, based upon type-face font etc., to simply be a partial printout from someone's air ticket or reservation. If so, that is definitely not "Official". Simply because an Airline has jumped the gun, and added this note to their computer reservations doesn't make it so. Finally, I also question your comment that CAAT allegedly has this authority on their own. Show me where you get that from too. Otherwise, I respectfully disagree. My understanding, is that any "authority" by CAAT to impose health-related restrictions, is and must itself be derived from Official Policy from the Ministry of Health.
Again, simply repeating that "This is the Notice", doesn't suffice for me as "Official". If you have a weblink to the CAAT website with this Notice, that would be satisfactory,. Otherwise, the image you have posted, could have come from anywhere.