For Librem laptops, true. I don’t believe this applies to the Librem 5.
This is perhaps more likely to be the complication over exact card firmware version + card operating mode + actual hardware that needs to work: Wifi/bluetooth issues
To be clear, with my Librem 5 still running Amber … Bluetooth and WiFi both work fine with no card firmware in the root file system at all and with default operating mode.