This is a good suggestion to stop streaming to the OPN so that the iPhone will reroute the sound through its loud speakers, but it’s not really the same as a Disconnect. The OPN technically is still connected to the iPhone, it’s just that it won’t stream even though connected.
This may seem like splitting hair by definition, but the difference is that usually a re connection may take up a few seconds to re establish, while re enabling the streaming is almost instantaneous once you’re inside that menu.