Will Apple ever be able to get the Apple Watch O2 sensor equivalent to a pulse oximeter?

I read conflicting stories on how accurate it is. And my sleep apnea doctor says it’s not accurate.

I have a pulse oximiter also, but I can’t wear it overnight. So I can’t match it to readings with my Apple Watch when I sleep. Over the last 6 months on occasion my numbers go below 90, sometimes below 85, and once below 80. I hope Apple is working to get it FDA certified. We just don’t hear much about what’s happening.