Even if that was sufficient understanding, neither of those gentlemen seem to absolutely reject death as the natural order. Nor, for that matter, do Harry or Eliezer. They reject death as proper and good, but I’m confident that most would admit that it is natural. The other people present don’t seem to do that, though, and would be unlikely to be able to cast a True Patronus.
Even if that was sufficient understanding, neither of those gentlemen seem to absolutely reject death as the natural order. Nor, for that matter, do Harry or Eliezer. They reject death as proper and good, but I’m confident that most would admit that it is natural. The other people present don’t seem to do that, though, and would be unlikely to be able to cast a True Patronus.