

As long as your headphones are Bluetooth, they will continue to work fine.
I haven’t run Graphene OS since I broke my Pixel 3a and went with a different device. But when I did run it, it was perfectly fine.
With that said, I ran lineage before I ran graphene and I ran lineage after I moved away from graphene.
I wouldn’t say it runs at the best, but currently I’m using a OnePlus Nord N200 5G