job_shredder69 You lost me at, "I don't see the term AOSP".
Just as some computers run Windows and some computers run macOS and some computers run Linux, and they are different operating systems, some Google Pixels run Google's Pixel OS and some Pixels run AOSP and some Pixels run GrapheneOS, and they are different operating systems. They are related but they are not the same. Nothing automatically moves from a release by Google of Google's OS to anything else. Also, nothing automatically moves from a release by GrapheneOS to Google's OS (for example, Google's OS does not have duress PINs).
Google releases some features of their OS to AOSP, at their discretion. If and when that happens, other organizations, such as Samsung, Sony, and GrapheneOS, can deploy those features. GrapheneOS generally does, and generally very fast.
But Google does not release all of their features to AOSP. As long as Google has not released Bluetooth battery rings to AOSP it is genuinely quite likely that Bluetooth battery rings will not be a feature of GrapheneOS.
Articles in the press are almost always about Google's OS. That means that some features mentioned in those articles will show up in GrapheneOS quickly (the ones released by Google to AOSP) but others will show up in GrapheneOS after a delay (if Google eventually releases them to AOSP), and some will never show up in GrapheneOS. Articles in the press will generally not say which features are in which category.
Typically if an article says a feature is part of Android 15 QPR2 and GrapheneOS issues a release based on QPR2 and that feature is not present, that means Google is keeping that feature to themselves rather than releasing it to AOSP, in which case there is no telling if or when Google might release it.
job_shredder69 My theory for not releasing it might be that the live image needs to be pulled from Google's servers instead of locally.
Nothing moves automatically from Google to GrapheneOS. The things that do move are manually released by Google to AOSP and then manually imported from AOSP by the GrapheneOS team. What moves is source code and firmware blobs, not "live images".