This is nonsense (the tricky part), esp. when it comes to a software giant as Blizzard.
Virtually any ssl/https library allows custom certs that can be shipped along with the executable.
It's awfully common to see clients (enterprise) with trust-all keystore.
Any reasonable one would allow you to change the trust store or approach programmatically.
My argument was that centralizing trust as a service is unsustainable. That's all.