utter rubbish. Once you become tax resident regardless of the visa you are on then if you remit foreign sourced assessable income it may attract a Thai tax liability.
Thailand doesn’t tax worldwide income. Thailand has a remittance based system. Once you become tax resident any foreign sourced assessable income remitted into Thailand may attract a Thai tax liability.
My question would be how do you intend to live for 5 years in Thailand without remitting funds?
you obviously are not up to speed on how Thailand operates. Banks no longer open accounts for people on tourist visas due to increased AML/KYC checks driven by a change in law making the banks responsible for any fraudulent activity. Going to a different branch or different bank is not going to make any difference whatsoever.