Yeru,
I didn't know at first that I was speaking to his wife, I just called the Church. Actually I called a local Lutheran organization in that city that was only too happy to give me the number of the Church, and Audrey Rydbom answered when I called the number. It way too easy! But this is a rather sensitive issue now, but she appreciated a sympathetic ear, and that I could sense the tough situation that had been created for her. She talked about how difficult it's gotten with so many people calling, and I apologized and started to say good-bye, but she was happy to continue talking.
The most straightforward explanation is the one you gave, that your friend, the Major, liked the letter and sent it out because he believed it would be valuable support to everyone who believed likewise. No harm done. If he was the one who edited out Major Rydbom's info, then he made a mistake, but I'm sure he meant well, and was sure at the time it was for the greater good. It's just as possible that he received it like that and didn't even know it had been edited.
It's not much of a stretch to believe in the scenario I'll propose below. I am beginning to believe it after speaking with Audrey Rydbom, although I didn't mention it to her:
The Army already knew that Maj Rydbom's writing style was well received back home, that his previous monthly letters were already getting publicized on a small scale. So they encouraged him to send a version that more succinctly included all of the important arguments that they were already trying to get across to reporters in Iraq. (One of the forums discussing this letter links to a FOX News interview with a General that hits all the same points the Major made, but from the viewpoint of the General.) I don't see how the Army would have any trouble helping Major Rydbom get this special version of his letter distributed much more widely than his previous letters. This was the one they helped him edit specifically for wider distribution, after all (imo). I don't see how Major Rydbom would object because he obviously believes in the media briefing points anyway.
Army divisions in Iraq may have even encouraged other Majors to send the letter in the ambiguous manner your friend utilized so that recipients would be more likely to distribute it more quickly. This way they could create a potentially large Internet news blitz, to help counteract the failings of US news media. This tactic may have given some of the senders the impression that they had the right to edit it even further which would explain the WOMD additions and a couple other changes on other versions that Maj Rydbom and his wife specifically deny.
Gamaliel