Interesting thing I just noticed with Bluetooth headphones (AirPods), but I’m not sure if this is new to this beta or has been discussed already.
When you toggle the Bluetooth off from the CC, of course it disconnects from your AirPods. But rather than having to toggle it back on and reconnect, you can go straight to the audio output button in the CC and still select the AirPods, even with Bluetooth still toggled off, and they will reconnect and toggle Bluetooth back on. I’ve found this is faster and easier than toggle-and-reconnect, and a nice feature for when you want to put the AirPods in your pocket without the case but don’t want audio being diverted through them.
Yes, it's because the CC buttons no longer actually turn off BT or Wifi, they just disconnect any existing connections until the user takes some manual action (either toggling the radio back on in CC or manually initiating a specific connection, as you did with the AirPods)