I was expecting something jaw-dropping when I started the article but on reaching the end I can't help feeling "ho-hum". It the kind of thing that's fairly obvious if you think about it. Of course, like many of these obvious "new" threats the claims are over-egged.
The persistent host portion allows network prefix randomisation to be unscrambled, it do not allow further tracking of other devices in the network. In the example given you can't confirm the laptop is the same machine as yesterday, only that it is a system on the same network.