There is some evidence to suggest that the folks over at Google are already testing the Google Pixel 2, or at least one of the new Pixel phones. This comes from code commits in AOSP that were recently spotted which seem to indicate that one of the three new phones from Google might already be available in hardware form. The comment that is specifically attracting the attention came from David Zeuthen (a software engineer at Google) and reads as follows: “finally got around to manually testing this on a walleye device.”
Now of course, "walleye" is one of the codenames that is rumored to be in use for one of the new Pixels. This is along with "muskie" and "taimen". Although, there is still some debate about the nature of taimen and while it is rumored to be a new (third) smartphone from Google, it is unclear if it will be branded as Pixel. In either case, walleye is thought to be the smaller of the new Pixel phones and therefore, the likely successor to the standard Google Pixel.
Back to the news at hand though, and while this is very little to actually go on - as there could be a number of reasons for a comment to be made like this - it does lend to the notion that the 2017 Pixel phones are already circulating the Google ranks, in some capacity. Of course, that might not sound that surprising as it would be expected that any manufacturer would internally be testing a smartphone early to iron out any potential issues with the hardware, or the integration between the hardware and the software. However, the question here is how early is too early? The current Pixel phones are still new by new standards and the new Pixels are not expected to arrive until much later in the year. In fact, they're not even expected to be announced until October, let alone become available. Although, if Google is testing these phones early, while also readying Android O, then there could be an argument made that the 2017 Pixel phones may arrive a little earlier than expected. Either that, or Google really is looking to ensure that when they do arrive, they have been tested extremely thoroughly. Which in either case, is probably welcomed news to those planning on picking up a 2017 Google Pixel phone.