That is the position that we have: Metadata is information about information. It took some time to wrap my head around that, because you're quite right that it's not exactly clear.
The language of the bill is kind of a thin veneer. As I read it, it's not a great leap to learn, for instance, that device X was communicating with device Y, even if the content of the communication isn't clear, especially given the fact that all sorts of related information is also up for grabs. Presumably, the point of the investigative powers is to gather as much as necessary to positively identify an individual, particularly, to echo Ms. Saad's comment, when we talk about the definition of subscriber information.
Taken together, you have a constellation of information, and that's what the metadata is: device X talking to device Y. If that's being held onto for up to a year, it's actually difficult to grasp and comprehend how much communication is caught by that. It's an important point.