Is It Safe to Fly into Hua Hin on an International Flight Without Health Insurance?

I would say you're just asking for trouble "testing" this out. You have an O-A you entered on Oct 30th 2019 so you're good until Oct 2020. Sit tight, get your current year, when that's running out bounce out and back to get the final "second year" and buy a re-entry permit.

Just so we are all clear

There is no actual clause that says people who got the visas BEFORE the change don't require insurance when entering thailand AFTER the 31st of Oct 2019..

That's actually a misinterpretation of the rules. It's people who got the visa before the change were not required to have insurance when they BOUGHT the visa. There is nothing (as in not a single word) that addresses the fact that people who got the visas before the change don't need insurance when entering the country.

That is just the thaiz not really knowing what the rules say (and it's why most people who have visas from before the change get in without needing insurance).

That is also why some skate thru, some get hammered about it but get in for their year stamp but some get in only on a 30 day visa exempt entry.

Daniel you should be fine. Good Luck.