The only question is whether the mirror will be listed. >I would remove a link to ycombinator.com from a page I controlled

Let me reword this then. Why should an entity remove something from their listings when the offended entity can remove it from the local listing on its machine? The thing is - in the first case we are talking about public lists available for everybody. Why should the majority of users be left without and additional source of distribution (for example)?

But yes, obviously it's up to Arch maintainers wether they want this to be there or not.