My complete sentence reads: "However my insurance does not want to commit and offers me either that or the new 3.5 Million scheme."
The requirement still being the old one can be traced back to the paper "THE GUIDELINE ON THE AMENDMENT TO ADDITIONAL CRITERIA FOR PURCHASING HEALTH INSURANCE OF NON-THAI NATIONALS APPLYING FOR NON-IMMIGRANT “O-A” VISA (1 YEAR)", written by the Ministry of Public Health - Department of Health Service Support. Which is obviously not Immigration. The relevant footnote on page 4 of this document reads: "The [draft] will take effect on 1 October 2022. Currently, non-Thai nationals who intended to extend the visa shall follow the criteria prescribed in 2019. Details are shown in the table." (Note the OCTOBER date, which is one year after the change for INITIAL O/A visa applications.)
The requirements for extension of stay listed on the Immigration Department website are the same they have been for many years, not mentioning health insurance at all.