I know Thai bargirls with millions of baht in the bank, and they don't pay taxes. That would be low hanging fruit for the Revenue Department, but they don't bother.
The only wrinkle is if a tax return is required to renew a visa. No sign of that yet.
You are making some big unfounded assumptions. The changes to the Thai tax regulations carry the power of law and require all tax residents remitting more than 150,000 baht (with certain exceptions) to file a tax return. If only to document that you don't owe anything.
The Thai Revenue Department is not being clear on the details. It seems they came up with the idea, put it in the regulations, and then forgot about it.
Lots of people panicked and applied for a Thai tax identification number, and were turned down.