Finding an optimal donor match (via HLA typing) rarely returns many "perfect" matches. Perhaps there are systems that record both the CCR5 mutation and HLA typing, but I'd expect most donor matches, found via registries like https://bethematch.org/, will not have that information available.

I haven't dug into the weeds here (and, for personal emotional reasons, I will not), but I find it hard to believe the medical staffs would have seriously considered "can we find a donor that matches AND will possibly cure the HIV". The diagnosis-to-death timeline for many blood cancers is fast when other treatments don't work. Delaying a transplant by 2 weeks in order to find a slightly more optimal donor seems crazy. (Though I suppose the after-transplant care for someone with HIV might be trickier than those without HIV. But patients will be immune-compromised for at least months post-transplant, so maybe HIV isn't that big of a deal.)