I think your cousin was talking about this
add SystemUI and Settings integration for detecting and notifying Pixel 6a users with batteries impacted by the fire hazard issue resulting in capacity and charging being throttled along with directing users to the support options for getting a free battery replacement, $150 credit or $100 cash as compensation for the faulty battery (a subset of this will be replaced by AOSP code when Android 16 QPR1 is finally pushed to AOSP)
which was added in this release. So yes it did get added to GrapheneOS