The BT SIG moves kind of slow and there's a really long tail of devices. Until there's a chip with native Opus support (that's as cheap as ones with AAC etc) you wouldn't get Opus support even if it was in the spec.
Realistically for most headphones people actually buy AAC (LC and HE) is more than good enough encoding quality for the audio the headphones can produce. Even if Opus was in the spec and Opus-supporting chips were common there would still be a hojillion Bluetooth devices in the wild that wouldn't support it.
It would be cool to have Opus in A2DP but it would take a BT SIG member that was really in love with it to get it in the profile.
Realistically for most headphones people actually buy AAC (LC and HE) is more than good enough encoding quality for the audio the headphones can produce. Even if Opus was in the spec and Opus-supporting chips were common there would still be a hojillion Bluetooth devices in the wild that wouldn't support it.
It would be cool to have Opus in A2DP but it would take a BT SIG member that was really in love with it to get it in the profile.