Now that Android O is on the horizon, it seems like many phone manufacturers have opted to completely ignore Android 7.1. A few devices have been updated, such as the OnePlus 3/3T and Nextbit Robin, but not many. Now it seems the Moto Z Play has become Motorola's first phone (in the US, at least) to get Android 7.1.
In addition to Android 7.1, the update also includes Duo for video calling and "updates the Moto Mods platform to the version 2.0." The June 1st security level is also included. You can see the new features in Android 7.1 here, but keep in mind some of those abilities (like the fingerprint gestures) might not be available on the Z Play.
In a similar note, Motorola seems to be rolling out Android 7.1.1 to the Moto X Play in India, but that could just be a soak test for now. You can find more information about the Z Play's update at the source link below.