They are probably not talking about whole blood, but how many lives based on the amount blood products, like plasma or platelets.
I think the number is still inflated beyond reason.
I have a brother (who is not gay) who can not give blood because he lost a finger. So, if you figure things like that and the fact of multiple same sex partners and the possibility of passing on not only AIDS but any other assortment of sexually transmitted diseases. Then the number of eligibles goes down considerably.
Here are the current FDA and /or AABB guidelines for volunteer blood donation (allogeneic and autologous) screening:
ABO, Rh Typing
Unexpected antibody screen (immunohematologic antibodies)
Hepatitis B surface antigen
Hepatitis B core antibodies
Hepatitis C antibodies
Serologic test for Syphilis
HIV-I/II antibodies
Human T-cell lymphotrophic virus antibodies
HIV-I Nucleic Acid Test (PCR)
HCV Nucleic Acid Test (PCR)
West Nile Virus Nucleic Acid Test (PCR)
Bacterial Screening of Platelet components
Additional tests may be preformed at the discretion of the collection facility, such as Cytomegalovirus (CMV) Antibody screening, Hepatitis B Nucleic Acid Testing (PCR) and T. Cruzi antibodies (Chagas' Disease).
So, multiple same sex partners mean the chance of getting clean blood is extremely low.