What are the current crop of cryptocurrencies that are truly anonymous? The list I have so far is: Aeon, DASH, Komodo, Monero , NAV Coin, PIVX, Verge, Zcash, Zcoin, and ZenCash.
This article feels like a puff piece for Monero, as opposed to a true discussion on the merits of anonymous cryptocurrency, which would minimally mention a subset of what you have listed above.
These coin all employ some anonymity features. Some real shallow (such a Verge only routing traffic over TOR) and some more elaborate (such as ZCash with zero knowledge proofs).
If you define truly anonymous as having no way to see transaction addresses and amounts, no way to check balances and history and these features all active by default... it would leave you with Monero and Aeon.
Of course other differences exist, such as vulnerable crytography (Zcoin), a potentially flawed "trusted setup" (ZCash, ZenCash), etc
Truly anonymous would mean if you bought $100 worth of anoncoin under your own name from an exchange and then played two hands of poker at an online casino, there would be no way for the casino and the exchange to collude and identifier you. Is that the case for any of the systems you listed?
Exchange gives you coin, and then have no way of telling what you did with it. Exchange just knows you are given 300 coins at the time of transaction, nothing more.
SafeCoin would be if it were actually implemented. As it currently stands, there is just a MaidSafeCoin token with a promise of a 1:1 exchange when SafeCoin gets implemented. Still, the concept is interesting. It's not blockchain-based, and a coin's data structure only contains the current and previous owner signatures.