While developers are getting their hands on the first beta of Android P, there's something else we need to talk about. Android P has chosen some specific hardware (for now, maybe): the Pixel, Pixel XL, Pixel 2 and Pixel 2 XL.
Minus those devices, it appears that Google's Nexus 5X and Nexus 6P will not longer receive love because they're being dropped. Android P will not support Nexus 5X and Nexus 6P as well as the often-forgotten Pixel C tablet. Ars Technica confirmed with Google, saying that those device will not be getting Android P when it's officially released to the public.
Android Police also notes that there's no Developer Preview image for the Nexus Player, which was introduced back in 2014, so it will likely not receive any future updates.
Mind you, all three device will receive monthly security updates through at least November of this year, but will remain on Android 8.1 for an underlying OS as far as Google updates go. This shouldn't come as too much of a surprise though. Let's not forget though that Google has done a good job of moving major features of its OS into its apps and services, and due to Android's open nature, the community often helps fill the gaps.