I seem to recall the UCMJ laws do not permit this practice. This is typical of liberals; long held laws that stand in their way are either eliminated or bent to their own purposes.
Another problem is the risk of introducing HIV into the blood supply. The FDA strictly bans all homosexuals from donating blood anywhere in the USA because of their increased risk. BO wants to now pump homosexual blood into the critical combat transfusion supply. That is pure insanity.