Google is already testing next version of Android called Nougat under beta testing. Android 7 Nougat is available under public beta testing and developer preview.
According to Telus forums, the Android 7 Nougat update could hit Nexus series of smartphone in couple days. Yes you heard it right, the Nougat update could come on Nexus devices on 22 August.
If the timeline is true then Google could release final version of Android 7 Nougat to OEM soon. Once the final build is released, manufactures will work on releasing the update to their smartphones.
This year Google started the public beta testing of Android 7 Nougat earlier, so the public release could be advanced as well. It will be first released to Nexus 5X and Nexus 6P devices only. The update could hit on 22 August.