Earlier quoted context omitted.
That is actually meant to keep the connection to a Bluetooth keyboard/mouse when using the computer in clamshell mode.
They don't let me use an HDMI display without external power while closed, so why let me use bluetooth without power?
Yet when my Macbook is asleep in my bag with no peripherals attached, my headphones will connect and wake the Mac.
The left hand does not know what the right hand is doing. It literally makes no sense.