In Android 8.1 Oreo, the maximum number of Bluetooth audio devices that you can have connected at one time is two: one for call audio, and one for media. But in Android P, there's a new developer option that allows for up to five --- yes, five --- of your Bluetooth audio devices to be connected to one phone simultaneously.

 

This new ability for up to five (or up to four, three, or two, depending on what you want) devices to be connected at the same time pairs well with the new 'Media output' panel, but it's definitely a niche feature. Just to clarify: this isn't for simultaneous playback, which would be much more complicated. Not many people have five Bluetooth speakers or headphones they need to have paired at the same time, let alone five Bluetooth speakers and/or headphones at all.

To enable this, you'll have to enable developer options by tapping on your build number a bunch of times in the 'About phone' section. But seriously, you probably don't need it.