Its not a whitelist of domains, but of applications allowed to use the agent. Right now Blizzard is blacklisting only the browsers from using it, but that still leaves a bunch of other things like slack and whatnot.
Its indeed a very strange patch from Blizzard. As if they hastily assigned an intern to it and then called it a day.
A blacklist won't allow items that match and a whitelist only allows items that match. Blacklists include by default and whitelists exclude by default.
Since the regex needs to match to be included - it is, by definition, a whitelist. It excludes by default anything that doesn't match. It just so happens the net being cast is so wide as to be "all except ____" where a whitelist is usually seen as "none except ____".
Think of it as shorthand for a list that expands to be infinitely large. [0]
People would consider a blacklist that includes ` * .example.com` to be a list that contains all potential subdomains of `example.com`. With ` * ` being seen as shorthand.
E: Spaces around the asterisk added to avoid HN formatting.
[0] Technical limitations aside, especially in the context of URL matching since URLs have a maximum character length.
If it's not a joke, it's at least an exercise in absurdity.
I wrote a regex that would allow things that aren't facebook, and then you said "No, you're not allowing things that aren't facebook, you're not allowing things that don't match not being facebook".
If it's not a white-list, it's at least an opposite-of-black-list.
If you think you need a blacklist you should probably be using a whitelist. If your problem can't be solved with a whitelist then it's probably better solved in a way that doesn't involve a blacklist or a whitelist.
Its indeed a very strange patch from Blizzard. As if they hastily assigned an intern to it and then called it a day.