It seems like the rumor is self-referential. Is there anything more substantial here?
Like the guy saying he didn't pick up when Meta called. Was it actually Meta? What are the conditions for the invitation? We'll never know, but apparently this is enough proof of both an NDA and Meta trying to force admins to do something they don't want.
Hopefully that explains it.
Whether that is concerning to you is up to you, but 2 of the people in question already stated it.