It was Tom Chilton who spilled the beans about Legion cresting 10M subs. It wasn't even in an English interview. It was an interview he did with a Polish gaming magazine. At the time, Chilton had Ion's current job so it felt pretty important. Blizzard then walked back the claim stating that it was a "mistranslation," but it does at least somewhat support the idea that Blizzard does like to brag when they have a lot of subscribers. Fairly immaterial for this discussion, imo, but a fun little piece of WoW trivia I guess.