BA cabins are hot enough as it is!

I find it hard to believe the virus will suddenly weaken over 25 degrees, humans run considerably hotter and it seems to do ok inside us! MERS, another coronavirus, was active in Saudi Arabia, though perhaps it stuck to areas with aircon?

Unless there's confirmation from a reputable scientific source, I'd assume it's internet rumour/urban myth that has been picked up and is driving the policy.