Well, the story is true. The OU is duplicitous about the status of oreos, and the mashgiach in question is reliable, and I believe him. I wouldn’t eat oreos with fleshigs, but I would right after. A parve food cooked in a dairy pot can be eaten even with meat, according to the principles of Nat bar Nat.
Chullin 11b says that fish brought up in a meat pot can be eaten with dairy.
The Rambam, Rabeinu Tam, and most Rishonim say that whether the fish were served, cooked, or even fried in a meat utensil, they may still be eaten with milk.
The Mechaber (YD 95:1) rules in accordance with the majority opinion, and allows fish which came in any sort of contact with a meat pot to be eaten with milk.
The entire issue of hezkat halavi/dairy equipment follows the chumra of the Rema, who holds like the Rivan (who says that the fish can’t be eaten with dairy), and says that something made in hezkat halavi can be eaten after, but not with, meat.
The Beit Yosef (YD 95) says that intentionally, one may rely on nat bar nat. Therefore, the entire DE controversy is merely a figment of the Rema’s decision to be stringent against the bulk of the rishonim. While I would accommodate guests at my home by following this, it is clear that one need not be concerned.
The Oreos themselves are parve, but cooked in hezkat halavi. According to the Beit Yosef and Hakham Ovadia Yosef, and the Pri Megadim, we can eat something made on dairy equipment even with meat.