Gateway as a speaker use case enablers must be integrated into Reference Kit. Pulseaudio needs to be enabled in refkit gateway profile. Documentation how to set up the speaker functionality and configuration for the Bluetooth speaker setup must be provided as part of this item.
pulseaudio has been integrated to gateway profile. Documentation is done but not integrated and checked. I will verify this week (ww12) that everything works as expected and try to integrate the docs.
pulseaudio and documentation is integrated (gateway image)
https://github.com/intel/intel-iot-refkit/blob/master/doc/howtos/bluetoothspeaker.rst