Back in 2004 they actually announced if you had been disfellowshiped or had disassociated. Now, they announce that you are no longer one of Jehovah's Witnesses.
I didn't send them a DA letter in 2004 when I decided that I wanted no more of their hypocritical behavior. I just told the 2 elders that were investigating me to see if I harbored any apostate ideas that by affiliating with the UN the Watchtower Society had turned apostate and I didn't associate with apostate religious organizations. I ended the telephone interrogation (I refused to meet with them in person so one of them called while he had the other one on conference call) by hanging up on them. 3 days later I received a phone call from another JW from another hall asking why I had DA'd.
The Watchtower elders will not read your DA letter other than to skim over it looking for the sentence where you tell them you quit. They don't give a rat's ass about truth or logic or honesty because they drink the WT koolaid by the gallon.
I suggest that you send your DA letter to the entire congregation and all your JW friends.
That will do more good than sending it to a group of men who care only about protecting the mother organization.