Frilly, I live in North Central Idaho, so it applies to the North sometimes too. Knowing that a plant is heat tolerant wouldn't matter to those who don't have the problem, just as salt tolerant or dry shade tolerant wouldn't apply to people who don't have that problem. But, those are both part of the plant database.
Also, just because a plant will survive in a warmer zone, it doesn't mean that it will survive in full sun, or high heat. I never use the "warmest zone" as an indication of how well a plant will tolerate heat. Some of those plants are for full shade only. I was kind of thinking that having this as a searchable feature would be very helpful. So, I wasn't looking for "full sun tolerance", but for heat tolerance.
