Torrentz was a torrent aggregator that got shutdown. It only linked to other torrent sites. It never had any magnet links or torrent files.
Did it not also search those sites and link directly to the search results page?
I'm also not quite sure how it got taken down. I'm currently not convinced that this site nor Wikipedia are illegal for linking to these domains. If someone can either convince Wikipedia to remove those links, or make a strong case for why this is different than Wikipedia linking, I guess I'll have to take it down, yes.
Why is Torrentz choosing to shut down relevant?
I think the difference is between linking to material directly, and to such a website. For example, I don't think linking to the Pirate Bay is prohibited.