In my opinion a solomonic decision on the part of General Mattis/Secretary of Defense Mattis pending a thorough policy review.  In the meantime, constructively I'd like to add my anecdotal proverbial "two cents" worth.

While I invariably have a laissez-faire attitude/posture towards others especially when it comes to interpersonal relations, I respectfully believe that U.S. military Commanding Officers in today’s military have just too much on their plates to focus effectively on the mission plus also to deal concurrently with the obvious travail(s)/the untold drama [and believe me when you're dealing with gays, lesbians and transgenders there is beaucoup drama] of dealing also with transgender personnel on a daily basis in U.S. military matters [particular during combat] too.

Fred Harden III AKA "GreyHairandGreyMatter"