You cannot be convicted for an action that was made illegal after you comitted it. This is just Facebook sucking data and making money off others' misfortune. I am sure that they didn't hand over the chat logs for free. "I got nothing to hide" is exactly the reason Meta is a multi-billion company. Your agenda should be "I have nothing to gain from sharing my life with them".
It's like "don't talk to cops, it will not help you".