Checkout the official list of Motorola phones getting Android 7.0 Nougat update. Though no mention about the exact ETA (expected time of arrival), according to the blog post, the Nougat update will be starting in Q4 with Moto Z and Moto G4th Gen. i.e. Moto Z variants and Moto G4 will get the Android 7.0 Nougat update by December.
Official List of Motorola Phones Getting Android 7.0 Nougat Update
For now, Motorola plans to upgrade the following Motorola devices; however, things may change in the future. Moto G (4th Gen) Moto G Plus (4th Gen) Moto G Play (4th Gen) Moto X Pure Edition (3rd Gen) Moto X Style Moto X Play Moto X Force Droid Turbo 2 Droid Maxx 2 Moto Z Moto Z Droid Moto Z Force Droid Moto Z Play Moto Z Play Droid Motorola Nexus 6 The list includes 15 models (the last one Google Nexus 6 already updated to Nougat), which means most Motorola smartphones users can enjoy all the new features of Android 7.0 Nougat within the next few months. (Source – Motorola)
