Google Assistant might come to Nexus 5X and Nexus 6P with next "major" update
It appears that at least two of Nexus devices will be getting the Google Assistant in the not so distant future: the Nexus 5X and Nexus 6P. According to sources familiar with Google's plans, Google Assistant will arrive on these two smartphones with the next “major” update.
Moreover, Google's Android TV director, Sascha Prüter confirmed that the Nexus Player will receive will receive the new feature as well. As to when exactly Google Assistant will arrive on all these devices, we're still in the dark. Although word is that it will arrive with the next “major” update, “major” could mean Android 7.1.2 or even Android 8 (or Android O).
All in all, those Nexus owners who can't wait for Google to bring its Assistant to their devices can install it through unofficial means whenever they want, though that will require a little bit of tinkering with their phones' software.