They’ve actually slightly improved this lately, they ask about what they determine are risky sexual behaviors (ie hookups) with no gender attached now. The one thing is that you can’t be actively taking PrEP and donate because it would obscure the HIV testing results (that they ought to be doing every time, multiple times!).
Source: https://www.redcrossblood.org/donate-blood/how-to-donate/eligibility-requirements/lgbtq-donors.html
My guess is that Judy Blume writes about girls going through puberty and getting periods as a normal, frank discussion of what that’s like. And any talk about the bodies of women and girls is indecent to conservatives.