What are the current requirements for the Retirement Visa in Thailand regarding monthly income and bank balances?

You have more than 65,000b being transferred from overseas to a Thai Bangkok bank account for every month for 12 months then yes

The monthly income method is still a possibility. But there are some caveats.

It looks like you are American? If so, the American embassy does not certify income, so there are a few issues you might run into.

If you apply for the non-O visa in Thailand, you cannot use monthly income for that. You have to use 800,000 in a Thai bank account transferred in from overseas.

You also cannot use the monthly income for the very first 1 year extension. You would need to keep 800,000 in the account for 2 months before applying for the extension, and 3 months after. Then it cannot drop below 400,000 until you receive your next extension (if you're going to switch to monthly income).

Finally, for the extension you need to show proof of 65,000 baht transfer into your bank account from overseas every single month for the previous 12 months at the time you apply.

People whose embassy will certify their income do not have this issue and can use that certification to both apply for the non-O conversion inside of Thailand and apply for the first 1 year extension.