I just searched 2020 explorer subwoofer and the video is one of the first ones listed. There is only a quick view of the wires coming from the back panel, no description or what they used. I am going to use the wire shown from the OP to get the subwoofer frequencies, I have a LC2i pro that will pick up the high level input and send a remote wire to the amp. It also has adjustable levels to help improve the signal to the amp input, converting the high level signal to low level rca. You can also add the remote from power at the dash, you would need a wire diagram or volt meter to find a switched power source. Unfortunately there is not a lot of information about adding subs to the my20-21.
7:45 explorer dash removal
9:45 short view of back wires with no description