The Daily Tracing Key cannot be "easily fingerprinted" since it does not leave the device (see page 5). Your LE threat model seems like grasping at straws, the majority of users already have location services enabled anyway, people breaking the law would have to change exactly nothing from the common practice of not bringing your phone when committing crimes.
I miss-spoke. I meant to say the rolling proximity identifier could be tracked and fingerprinted.
Furthermore, it's not the same as a phone's location implicating you in a crime. It's a persistent log of your in-person social network that can be reverse engineered every time you get arrested or go through customs at the airport.
The rolling proximity identifier is short-lived and put through a non reversible cryptographic hash function to prevent exactly that, same page. You're not going through airports in a pandemic, after which you can uninstall whatever app you're using in this crisis.
