Yes, the FSF thinks a device becomes more free if you destroy the ability to update the software that runs on it.
WiFi presents a particular problem for free software because to sell a product that emits radio waves, it has to be certified (by the FCC or other national authorities), and they won't certify something that could be trivially reprogrammed to exceed legal power limitations or broadcast outside licensed frequencies. It's easiest for them if the user can't change those details at all.
* Most "firmwareless" devices have firmware ROMs anyway. The FSF only believe it counts as nonfree if the users can see the firmware in /lib/firmware; they are happy to endorse products with hundreds of kilobytes of nonfree firmware ROM as "respects your freedom", since users can't see the blobs.