I've heard that semantical argument for years and years... to me, and maybe I'm letting it get the best of me -- but it's just that: semantics. It's almost like when someone asks a rifle shooter what "minute of angle" means, and someone answers "one inch for every 100 yards." The semantically correct answer would be to say, "No, that's wrong." If you answered that way, you would technically be correct (since MOA is actually 1.0471996 inches at 100 yards), but the person asking the question is still left wondering why not.

No, it doesn't change the BOW'S draw length ... and technically, it doesn't change what the shooter's draw length SHOULD be. Problem is, it changes his effective draw length all things being equal -- because it will move a shooter's anchor point rearward by whatever length the d-loop adds past the point as if he were shooting "off the string." Sometimes this can be a good thing, sometimes not; it all depends on how properly the bow was fitted to the shooter before the addition of a d-loop.

In my case, I'm a true 29" draw length when shooting off the string... I have to shorten my dl anywhere from 1/8" to 1/4" when adding a loop, and that's largely because I tie them so short and use a release head specially designed to not lose dl when using a loop.