The did add health insurance to the 0-A visa, during covid, and that makes sense, since more than a few were stiffing hospitals.
So, folks on a Non O weren't stiffing hospitals. Only the OA folks. I started with the OA, Covid came and couldn't leave to reset the OA for 12 months. Used an agent who for 3K got me a BS Ins policy. Requiring the OA's to have Ins and not the O's seems weird.