I don't know. Like I said, those who make mead are adamant that boiling is a sin.
However, you're not making mead, you're adding honey to beer. So maybe latent bacteria that wouldn't stand a chance in an all-honey must (what a mead-maker calls wort) could take off and bloom in your beer.
However however, I do know that boiling it does take a lot of the flavor away. I've had firsthand experience making mead by boiling and by not boiling, and there's no comparison.
However however however, I've made a few batches of a honey porter, following the directions on the recipe from my LHBS, and that does have me add honey to the boil, about 10 minutes before the end. And that is some mighty tasty beer!