The solution is very simple.
engage in homosexual sex and no blood donation allows (already the rule)
so
engage in homosexual sex and no organ donation allowed.
Bigot!!! /sarc
Of course, being on the honor system, the donor could just lie, as they are encouraged to do by some ivy league college homo-activist groups. Unless I missed it, this article doesn't say that the donor was identified as an MSM before donating, so he could have just violated the honor system - which should be a criminal act, in my opinion.
Hmmmm ... possibly.
But two caveats. FIRST, by your reasoning why should a potential organ (or blood!) donation be foreclosed if the only person with whom the donor is having sex is the recipient? So ... I would for sure make that exception.
The larger idea must be that we restrict rights no more than absolutely necessary; that we have a compelling public interest that can not be addressed in any other reasonable fashion; that we adopt the narrowest possible reasoning; that we mitigate the consequences to the affected groups as much as possible; and so forth.
SECOND, I’m not trying to be difficult, but your rule would cause a lot of deaths, just as a simple empirical matter. Many gays are responsible organ donors, and their donations are life saving. This is not true of blood donation.
I think your rule is too blunt.