One thing that the bot is missing (just my opinion, obviously) is a pseudonymous identifier. I realize this technically does not make it anonymous anymore, but I don't think it matters.

For example, if you post anonymous feedback saying "the toilets should be cleaned more regularly" and you then post an anonymous comment to that post saying "I agree", there's no way of knowing if consensus is building or if someone is astroturfing the discussion.

Compare this to if the feedback is posted by anonymous#f46d and the reply is posted by anonymous#6c7e, at least you know it's different people making the posts.

Me too. The need for anonymous feedback is a symptom of a broken culture. If I were manager at one of these companies it would become a top priority to rectify it.

There is a need for anonymous whistle blowing, but that's not the same as feedback.