this article is a mislead
This arcticle title is a completely mislead.
Warden itself is not encrypted. What they are doing is to distribute different copies of warden (lightly different in code but provide the same basic functionalities in order to prevent some of warden anticheat-bypass technique).
From the software company side, they have their right to protect the software/game from reverse engineering. Alot of software companies are using strong binary packer (with encryption, anti debugging, ...), code obfuscation, and strong licence scheme for their products in order to prevent cracking, reverse engineering, ....
Using a different random cryptographic hash function in each copy of Warden is nothing wrong and surely customers will not lose any "potential safeguard". Just like you use randomly MD5, SHA1 or SHA256 hash functions for checking the malicious/cheat tool to prevent some kind of cheating. If one blames that the implementation can be exploited by Blizzard or an employee of Blizzard, please think again. Once you've installed any software/game on your computer, you have to trust it, either main binary or its components. The hidden malicious code can be anywhere such as inside huge WoW binary itself but not warden. I don't see any serious issue here.