The only Nexus device which has received its last version upgrade to Android 7 Nougat, Nexus 6, is due for Android 7.1.1 in January. There’s some glitch that has caused the delay in the update.
As per the sources claim, Google didn’t specified any reason behind the delay but they quoted in a statement that:
Unfortunately, we found a last minute bug that was specific to the Nexus 6, which has caused the delay of the 7.1.1 OTA rollout. We’ve since fixed the issue and will be rolling out an update in early January.
Already, as said above, Nexus 6 has already received an update to the Android 7.0. So, the users are not so impatient about the Android 7.1.1 update. Indeed, it also packs many fixes and features. Nexus 6 is going to be the first device which will receive this Android 7.1.1 Nougat.
Additionally, Pixel and Pixel XL has already received Android 7.1.1 update.
Nexus 6 is a device launched in the November of 2014.