I think you are accurate. And, I did have an O-A a few years prior to 2014 but got turned down renewing since my 800K was in a 'mutual-fund-fixed-account' rather than a 'fixed account' - and had to start all over again, thus I have an O visa now.
I appreciate the info, but wonder if what you say are real facts - how do you actually know this? Why would it make a difference if the original visa was O or O-A? Or is it a blunder from immigration side? If so, it will likely be adjusted soon.
I have a stamp that says O, transferred from my old passport. Cheers!