You said it was pretty standard for bug bounty programs, and I disagreed pointing to several of the largest and longest lived bug bounty programs, none of which do that, and your response is pointing out that one particular platform does it?

Even among 3rd party platforms, of which there are several bigs, the NDAs are not a platform requirement, just an option for participating firms.

NDAs are not the norm. Don't mislead people who would otherwise get into this game with non-issues they need not worry over.