Which is down to the varying desires of the community and the administration. The admin/mods have at least in part a goal of promoting their commercial ends whilst the community in general are neutral wrt those same ends. If the mods upgrade YC companies visibly and downgrade competitors, for example, then the chances are that will cause problems between the admin and the community.

Based on that I can't see YC ever agreeing to do their moderation in public. I think we have to remember that this is not a neutral forum but has an inbuilt bias, through moderation, towards the administrations benefits.

I'd be all for tagging a generic "Downvoted by moderation" onto any article this happened to. The poster will probably still be annoyed, but I imagine most would agree with moderation most of the time. And if they like, they can contact.

What they're less likely to agree with is this happening invisibly. And if it's invisible, then how do we know whether we (as a community) agree with it or not?

PS: Side note, strongly against "toggle a non-default option" as a solution. Filter bubbles are incompatible with democracy and true, diverse community.