HTC's U11 flagship seems to contain system code that makes references to the Pixel 2 family, meaning that HTC may have been developing the phones at some point, or may still be working on them. The find was made by Japanese HTC fan blog HTC Soku, and was found in the Taiwanese variant of the HTC U11. The flagship's system code seems to contain a list of devices HTC is working on that use Qualcomm's Snapdragon 835 processor, and among those, S2 and M2 can be seen in the list. Early on in development, the first gen Pixel devices were referred to by some internal sources as S1 and M1, which is how the leap to this implication was made.
HTC handled the first generation Pixel devices, so the code seen here may well have been a placeholder because HTC planned on getting the contracts for the second generation, after the first Pixel devices met with an adequate measure of success. HTC might also have actually been developing the two devices, or at least one of them, at some point. There is no evidence as to whether or not that is the case right now, but it is worth mentioning that "muskie," a device that popped up in AOSP and was said to have been a version of the Pixel 2, has apparently been cancelled in favor of the larger "taimen" device. It is quite possible that muskie was one of the Pixel devices that HTC has listed in this file.
As things currently stand in regards to Pixel 2 rumors and leaks, signs point to LG being the one to manufacture this year's take on the followup to the Nexus bloodline. A bug report log surfaced that implicated LG as the manufacturer for the taimen device. Numerous unofficial renders and concepts have been popping up, but thus far, nothing material or official has leaked as far as pictures. A leaked benchmark, however, revealed that Taimen is running the Snapdragon 835 for now, so if a bump up to the upcoming Snapdragon 836 is in the cards to mirror the first Pixels' bump up to the Snapdragon 821, it will happen later in production. Predictions are pointing to a large device because of the codename; Google's fish-based naming convention for Pixel and Nexus devices over the years would see the taimen, a roughly 220 pound titan of a sea creature, far outweighing the muskie that represented the first rumored Pixel 2 device.