Thai Bankrules have been tightened, because too many people has misused the Thai Banks, laundering money, and trying to hide money away from their homecountry.
But it is not only Thailand, where money needs to traceable etc. it is going in tha direction in many countries.
Been coming in Thailand for close to 30 years, different lengths of stay ( 2 weeks - several months) and never needed a Thai bankaccount, since I have my income outside of Thailand, and that’s where it is needed to have a bank, customers can pay to.
Search the group for the specific Embassy you will apply at, but best to do it in your homecountry, better chances to get documentation approved, since they know how documents from homecountry look.