Well, you should know that if you're sporting a rooted Android Nougat device, you can enable the Google Assistant on your device right now with a pretty simple edit of the build.prop file. But before we share the wisdom, let us tell you what the prerequisites are. As we mentioned, you need a:
• device running Android 7.0 or higher;
• the latest Google app installed (version 188.8.131.52 or newer).
You will need to add the following line to the build.prop of your device to enable the Google Assistant on your phone: "ro.opa.eligible_device=true", sans the inverted commas. After you paste it and apply the changes to the build.prop file, wipe the cache and the data of the Google app and reboot your device. If it does not appear right away, wait for a while and reboot again.
Alas, there's a chance that this trick won't work at all for you.
As we already reported, Google Assistant will remain a Pixel/Pixel XL exclusive for the time being, arriving along with Android 7.1 in the coming weeks.