Without going anywhere near how "absurd" or "dangerous" treating phone traffic metadata differently than the phone traffic itself may or may not be, it's certainly not new. In the US, at least, who you called, when, and for how long is subject to much less legal safeguard than the content of the conversation had, and has been for a very long time.

Of all the things to take from this article, to my mind, that's not the first.