I might be misreading your response but just to reiterate: Asking if Uber has a reputation management firm to handle stuff like this is like asking if they have

I might be misreading your response but just to reiterate: Asking if Uber has a reputation management firm to handle stuff like this is like asking if they have tax lawyers. And a professional, expensive firm would certainly have enough clean accounts to do this undetectably if that was even necessary (no idea what detection ability HN has). In my opinion that's the most plausible answer to why, but it's not the only one.