I fully expect to get downvoted for this, but it's an important point that I have to address.
> Some non-zero percent of those 12k people live with a partner who doesn't know their HIV status. It is totally unethical for those people to fail to disclose their status to their partners
This is itself based in old misinformation about HIV that serves to perpetuate harmful stigmas around HIV.
HIV is treatable, and when properly treated, cannot be transmitted[0]. That's not even taking into account other forms of HIV prevention that are practiced to reduce the risk of HIV transmission. While it's advisable for an HIV- to ask their partner's HIV status (and HCV, and other STD statues), a person with HIV under proper treatment should not be expected to proactively disclose that to every partner or potential partner, and it's not "totally unethical" for them to make the decision not to volunteer that information unasked.
[0] Decades of misinformation have drilled the false belief that HIV is always infectious into people's minds, to the point where public health groups are literally launching massive campaigns to correct this belief.