I think there has been a mix-up somewhere. The blog links to this article: http://www.learner.org/channel/workshops/nextmove/metaphor/airtraf.html
However, if you listen to the clip on that page, it doesn't sound like 'Boston John' at all. The 'John' on that page has a distinct Hispanic accent, which I have never heard from 'our' Boston John.
Your thoughts would be appreciated.
I don't know what to tell you. I was just going by the name. If it's not him, I certainly do apologize for getting it wrong, but I thought it sounded like the same voice...just a little quieter and more subdued (possibly letting his accent come out more) than he does on the Air Traffic radio. I could be completely wrong, though; it's been known to happen...often.