I saw this on Thai-visa-.com. The OP has always seemed to be knowledgeable and level headed. She wrote to the US Embassy and here is their response.
Thank you very much for your email and this on-the-ground perspective. Over the past six months, we have been engaging the Royal Thai government (RTG) to attempt to ensure that U.S. health insurance policies can be used to satisfy the new immigration requirement for health insurance for foreign retirees. This advocacy was done by official Diplomatic Note, as well as during the recent RTG press conference announcing the policy. During that event, the Consul General cited US veterans with TRICARE coverage specially as a population of concern in Thailand. At least one other Embassy (the UK) cited concern as well.
The U.S. Embassy plans to continue our advocacy with the RTG regarding the option for U.S. citizens to use existing insurance – regardless of where that insurance is based – to meet the requirements. We acknowledge there could be a difficult transition period as the Thai’s determine exactly how to implement the new health insurance requirement. As you note, the language in the official police order is vague in some respects. Therefore, we may have some room to navigate and improve on implementation.
Ultimately, this is a Thai regulation and the Thai government is the final arbiter of how this regulation will be implemented.
Again, we will continue to engage with the RTP on this issue.
Respectfully,
ACS"