May depend on Bluetooth profile i.e. if a device wants to be a straight audio sink or source, or a keyboard or a mouse, it should work - but if a device wants to use Headset Profile (HSP) and Hands-Free Profile (HFP) that may not be supported yet.
Refer: Frequently Asked Questions · Wiki · Librem5 / Librem 5 Community Wiki · GitLab
My Bluetooth combined keyboard and pointing device worked. My Bluetooth speakers worked.
If you have a mainstream laptop with Bluetooth hardware and the laptop is running Linux then the test would be whether any random Bluetooth device works with the laptop. That tests the overall level of maturity of support for that Bluetooth device in the Linux ecosystem.