It says further down in the document (the bottom of the center column of page 4 of the PDF) that the wiring does not meet a standard issued in 2007, and that: "Since design changes must comply with FAA regulations, the FAA proposes to require changes to the wiring installation to meet the required physical separation between the horizontal stabilizer trim arm wiring and the horizontal stabilizer trim control wiring."
I think the document is saying that after the accident the FAA decided that the entire stabilizer trim system had to meet the standards current at the time the MAX was certified. But it's not entirely clear to me.