Fair point. For those customers where this is important, that information should be available to them.
In my opinion, a customer is unlikely to want to use this particular device without WiFi, and if the WiFi can’t be swapped out, the customer should either run PureOS or should run a distro that is less free than PureOS. (That’s still vastly superior to a duopoly device. My actual beef with the Librem 11 is the lack of a WiFi kill switch.)
… with care. Some WiFi dongles also require loadable firmware, which ultimately must either come from the firmware jail or from the operating system disk.
Perhaps Trisquel can utilize a firmware jail. Not out of the box of course. But surely if you are dead set on using Trisquel as a distro, it can be made to use a firmware jail? After all, you own the device - and that would be a freedom.
As a result you may lose your own personal FSF endorsement (and you wouldn’t want to make a commercial supply of such a configuration i.e. personal use only).
It raises the somewhat theoretical possibility that the firmware could be reverse engineered and freed. If the firmware is in a ROM inside the card then there may be no interface to access the firmware at all.
I suspect that sheer complexity has forced manufacturers to make the firmware available as a file but that now means that the firmware is available for inspection or even potentially alteration. Yes, manufacturers could go down the Intel route of encrypting (and signing) the firmware but …