Won't avoid tax as if tax resident IE 180days+ the new rules cover all financial transactions both in Thailand and elsewhere. Financial institutions have to declare internationally including Thailand.
That said I'm not sure Thailands revenue dept can cope with so many expats. Only K bank has sent forms. Can't see all the others doing same. Like other countries income tax depends on deduction at source or self declaration and with tax credits available for the 57 dual tax agreements little increased revenue will be generated