Not entirely correct 
The drivers are there but to operate the AR3k Bluetooth a binary only firmware is needed which we do not ship with PureOS. If you are OK with binary only firmware you can manually download and install it, it is included in the Linux kernel firmware git:
https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/ar3k
Cheers
nicole