Earlier quoted context omitted.
Generally, admitting that your product causes a medical problem makes it easy for people to sue you over it. You’re right that they could be sued even if they don’t admit it, but then they would have a defense which would be far weaker if they had already admitted it.
Especially true if you are holding evidence that you knew it caused medical problems, but ignored that evidence and continued doing stuff that made it worse because it makes more money . At that point you pretty much have to start bribing people to look away, like the cigarette industry is notorious for. Facebook has practically zero incentive to research damages they might be causing. Sure, they could do the ethical…
Members from the well-being team tried to conduct research but was refused do to it because of “legal and PR” reasons. The well-being team was shut down.
All this will come out in lawsuits if/when they happen. Likely through attorney generals and not individuals.