This article mentions Zcash, which means that folks will be showing up shortly to talk about Monero.
Ring signatures have been around longer than zk-snarks so time will tell on that comment.
I do however believe Zcash could be doing a better job for privacy, notably by mandating private transactions once the new "JUBJUB"optimizations have been merged [0].
[0] - https://z.cash/blog/cultivating-sapling-faster-zksnarks.html