You are carrying a time bomb, that phone (Nexus 6P) came with so many manufacturing issues that android 8.0 has added a special feature just to allow you to reset your phone in case of bootloop problems.
I assume they are doing this mostly because of an inventory surplus combined with "Pixel 2" less than a month away but it's still nice of them to do it even though these phones are a year out of warranty for a lot of people getting these replacements. Even with the Pixel 2 out they could likely sell the older Pixels for a few hundred bucks.