It's an invasion of privacy. Imagine that a post appears under your name with a date/time where you are supposed to be working. If you are paid by somebody else, this may get you into trouble, or even fired.
There is no privacy invasion here (that isn't even the right argument). If you think that HN misrepresents the data then sure that's a valid concern, but it's not a privacy invasion. But really, the HN date is when it got exposed initially.
Fortunately the moderation here isn't a faceless monolith and if you email them they would most likely be happy to cooperate with your concerns about this.