I've never seen that message, and having used a Pixel 2 for the last year I'd have been using these android versions much earlier than your device would get them.
Are you sure it's the Android version they are warning about, rather than some other aspect of the device? Though in my experience Play Store compatibility warnings can usually be ignored (the only device I've ever had them for is my tablet, and that's because it's a tablet - almost all of them run fine regardless).