I don't think that'd be necessary. Google's stated that SafetyNet's purpose is not excluding power-users, but ensuring the security model of the OS has not been

I don't think that'd be necessary. Google's stated that SafetyNet's purpose is not excluding power-users, but ensuring the security model of the OS has not been compromised, in order to activate certain sensitive functions (e.g. Android Pay). Given that developments in the root community are few but well-known, it'd only take a weekly visit to the XDA Developers forum by an intern to learn about any new rooting method, and not many resources to successfully block them. No need for a complicated (and expensive) information gathering and mining rig _for SafetyNet_. Could they be gathering that information with other purposes? Given that Play Services de-facto has root powers within Android, maybe.