The Google Pay app has been updated so as to display a message should a given phone be ineligible to conduct transactions using this method. This notification would apply to users who have rooted or otherwise modified their devices in a way that causes it to fail SafetyNet requirements. In addition, upcoming updates to this app will also be able to PIN-protect online shopping done through it.
https://www.notebookcheck.net/Google-Pay-can-now-show-SafetyNet-status-on-its-load-page.444697.0.html