Anyone trusting Facebook to follow basic human decency and, yes, laws, is a fool.
Anyone blindly believing every random allegation is also a fool, especially when the app in question has been thoroughly reverse engineered and you can freely check for yourself that it's using the same protocol as Signal for encryption
I don't have any proof that Meta stores WhatsApp messages but I feel it in my bones that at the very least tried to do so. And if ever that comes to light, precisely nobody will be surprised.