But isn’t the real issue for Purism whether the device requires firmware at all to reside within Linux?
Realistically, noone expects the manufacturer to release firmware as FOSS but as long as the firmware hides permanently inside the WiFi device (e.g. on board flash storage or e.g. on board non-flashable storage), it should be OK for Purism.
Conversely, if the WiFi device requires firmware to be loaded at boot time then that is not something that can be fixed in software (probably?!?). So in this scenario the only option would be to reverse engineer the firmware until it could be considered open source (and then it would be OK for it to reside within Linux).
So my understanding is that these Intel cards may well work fine on the Librem 14 but you have to compromise a little if you want to use one.