That was probably true whenever that vid came out, but now the toolkit, cfsm and dlc builder can all fix low bass tunings. CFSM can even do it in bulk to your whole library.
The fix is only needed for songs bellow low C, so B standard/drop B and lower will need it, not C standard Drop C as they are the lowest that still work fine without it. The people making the videos probably just misread this thread as it can be a bit confusing.
https://customsforge.com/index.php?/topic/5227-5-strings-bass-and-low-note-recognition/
Adding the fix to songs that don't need it will not really improve the detection and there isn't really any benefit of doing so as it'll probably mess up the tuning name and tuning sort too. Issues of note detection at low tunings can also be caused by a few other things like intonation and string gauge. Tuning a 4 string bass with a set of standard 45 gauge strings down to C standard isn't going to go too well and can cause tuning/recognition issues as well.