Have you read the last sentence of my post? To add to that many of the recent "frozen" accounts have been because the name of the account and the name on the Thai sim do not correspond so needed to be verified.
No, only long term visa holders can open a bank account, what happens once it is opened doesn't matter, it was opened correctly under the current guidelines
How will the bank know what your future visa status is after they have opened the account based on having a Non-O? The accounts being "closed" were opened on a tourist entry stamp (including DTV in some cases).
No they don't, all visas are valid from the date of issue and up to the expiry date of 90 days or 6months for tourist visas and 90 days for Non-O visas.