Google is not pushing Android 7.1.2 to the Nexus 6 or Nexus 9. While Google recently revealed that they were going to start pushing out the Android 7.1.2 Nougat software to users who are enrolled in the Android Beta Program starting from today, with a planned release of the software to all users a couple of months from now, they also stated which devices were set up to receive the software in an early build format, and both the Nexus 6 and the Nexus 9 were left out of this equation, leaving only the Pixel, the Pixel XL, the Nexus 5X, Pixel C tablet, the Nexus Player, and eventually the Nexus 6P to get a taste of the new release.
While this might be a little bit disappointing to those who are still owners of either device, the good news is that Google will still be sending out security updates to both the Nexus 6 and the Nexus 9 for a while longer as they're still both covered under Google's policy under the time frames for security updates. That being said, they're also past the time frame for regular software version updates, which means that Google is no longer going to be supporting either device going forward. This also means that Android 7.1.1 Nougat was the last official update that either device will receive.
With that said, it's not entirely impossible that both devices will still receive ample support from the development community in terms of pushing them forward to the latest version of Android software that Google offers. This happens with tons of different devices coming from various manufacturers, and it happens with many devices that are much less popular than Google's line of Nexus devices, so even if Google is no longer going to be officially supporting the Nexus 6 or the Nexus 9 with software updates, many users will likely be able to find the software that they need elsewhere, although it's always worth mentioning that users will want to proceed with caution when trying to modify their device software outside of any official updates that are pushed out by Google and its partners as well as the wireless carriers which those devices are connected to.