Ann: Update - Myanmar Banking Regulations, page-16

I suspect what they are targeting is foreign money entering the country. It MUST now be converted to local currency. Clearly, like our Russian friend, they need to prop up the local currency to reduce the costs of imports.
They aren't saying foreign currency already in the country will fall to this requirement. There will be a delay while the local banks run around like headless chooks, trying to complicate a simple instruction.