I did read that letter and think that indeed, the person is referring to rec.travel.air newsgroup since we all know that anyone who visits here knows this is "FlyerTalk" and how could someone refer directly to us in any other way?
As for OAG, actually, I've neve considered them a competitor since their focus has always been business travel in the broader sense with just a slight coverage of frequent flyer programs (complimentary rather than competitive). The unique thing is that when i started, I was an 8-page newsletter and they were a 80 page magazine. I'm now almost an 80-page magazine and they are now 30 pages and were delisted by Advertising Age. I actually used to write a column for OAG but when a new publisher came in, whom I had never met, he immediately sent me a "no thanks" letter, referencing the fact that he thought I was a direct competitor and stiffed me for payment of two columns they owed me and delted my name from several interviews that I had provided research for in articles to be printed. Needless to say, my opinion of how they run their business has ebbed ever since. But, I do wish them well.