Files such as hal8812a_fw.c [1] have large arrays that seem to be binary firmware encoded in text. My understanding is that source code is not available, so I believe the files are nonfree software, and should, in the short-term at least, be removed from Guix. Long term it would be good to get the source code (via reverse engineering or asking Realtek), but I imagine that would take a significant amount of time and effort (I do have a Realtek USB Wi-Fi card, maybe not with this exact firmware though.).
[1] web copy at https://raw.githubusercontent.com/aircrack-ng/rtl8812au/6c1b4a333b067eaddc9b8b34927019b41b99bc36/hal/rtl8812a/hal8812a_fw.c
