2006 accord power lock wiring question

I’m not sure if such a specific question is appropriate here, but: I have a 2006 Honda Accord Coupe EX with nav. and MT. The Power Window Master switch in the driver’s side door is from a 2003 model. I am going to replace it with a new 2006 model switch (the power window stopped working). On pin 21 (white wire) of the 2003 switch, someone has spliced in a wire and ran it out the door (into the under dash fusebox, I presume). What is the purpose of this? (As far as I can tell from the schematics, the white wire from pin 21 should be connected only to the Driver’s Door Key Cylinder Switch.) Should I cut the bodged-in wire when installing the 2006 switch?

Thank you for your attention.