https://9to5google.com/2025/03/26/google-android-aosp-developement-private/
Google wants to only publish source code with releases. Afaik this is pretty bad for GrapheneOS, as you use a lot of unreleased things, or fix bugs early.
Using Pixels still means fast support and updates, but probably not as fast, always a bit behind. Currently afaik, GrapheneOS often releases quicker than Google!