Oh wow, this is actually amazing. I'm really impressed with the work the GrapheneOS folks are doing. Ah, damn, it looks like they've dropped support for the Pixel 2. I have a Pixel 4 as my daily driver, but I'd prefer to try it first on a phone I don't use all the time. Ah well. Perhaps the 4 will still be supported whenever I get my next phone :)
You can still download the Pixel 2 images via getting the version from https://releases.grapheneos.org/walleye-testing if you really want to use it. There may be a final extended support release, but it's very insecure at this point and we won't be making those extended support releases for much longer.
At some point, the new hardware has been changed for good reason — exploits have been discovered!
Upgrading to a new-to-you few-hundred dollars Pixel every 2-4 few years isn't anywhere close to the expense of a new $600-$900 phone every 1-3yrs, the way people used to (and the way iPhone users still seem to).
Some non-Twitter prose about the Play Services support (though it doesn't include the tweeted info about dynamite support being nearly finished): https://grapheneos.org/usage#sandboxed-play-services