There's not really a ban on the KIA bracelet specifically. There are regulations for wearing the uniform and specifically jewelry, and Marines are not allowed to wear bracelets. This falls under that spectrum. Now, the KIA bracelet will be lumped into the same category as the POW/MIA bracelets, which are approved for wear.

I felt that justice had been served and that the world was, in some way, a better place for all of us.

Memorial bracelets memorializing prisoners of war, missing in action, killed in action, and those who died of wounds or injuries sustained in a combat theater are authorized.

James F. Amos Quotes