It's not open-source without the license. I think they may be confusing source available with open source.
In the case of JavaScript, obfuscation turns source code into a compilation result for performance and "security" reasons. It removes unused tokens, comments, spaces, newlines, etc. to reduce the data transfer size.
So, by definition, non-obfuscated code is source code, as it is the code the compiled or built product originates from. However, most sites on the web don't ship source code, only minified and obfuscated code.