There were never any laws about which visas were allowed to open bank accounts. It was up to each bank and often delegated down to branch level. Some banks now seem to be changing their own rules which they can do.
BB had more issues than others though. This was both in volume and bank staff facilitating scam accounts. My BB account is my secondary account used for Grab and beer money. It was opened on a visa exempt in 2017 at the BB Branch with the most current issues ie Pattaya Klang. Touch wood it has never been frozen or any updates asked for. They know my visa changed to Retirement.
To be fair unless I saw official communiques from the bank I would not be taking the response from one bank clerk as gospel. If you asked a number you would get a different answer from each. You just said you asked 2 and got 2 different answers.
When you say research on your own what do you mean by that. Online or physically on Thailand with Thai subjects or organisations. You are still not being clear.