Training on personal data people thought was going to remain private vs. stuff out in public view (copyright or not), are two different magnitudes of ethics breaches. Opt OUT instead of Opt IN for this is CRAZY in my opinion. I hope that the reddit post is WRONG on that detail but I seriously doubt it.

I asked Claude: "If a company has a privacy policy and says they will not train on your data and then decides to change the policy in order "to make the models better for everyone." What should the terms be?"

The model suggests in the first paragraph or so EXPLICIT OPT IN. Not Opt OUT