Thailand signed up to International Common Reporting Standards and started to comply last year. Information is automatically exchanged about banking transactions.
For those not wanting to pay tax they could become tax nomads and move around the region spending less than 180 days in any country. There is also talk of a Schengen style visa for Asia - spearheaded by Thailand. For anyone wanting more information on Thailand I can point them to an excellent website in Thailand.
The tax rules are already in place for Thailand. From 1 January 2024 All income earned or remitted to Thailand will be taxable for anyone tax resident in Thailand (living there for 180 days or more in the calendar year). They are considered tax resident in Thailand. The other change that is being talked about is Thai tax residents being taxable on their world-wide income.
I came back from Thailand a few years ago. Initially stayed with family and registered with a GP. Did not need to see one -just got back into the system in case I did.