High Output Alt & Factory Wiring Change?

[MyFriendScott]

Putting the finishing touches on installing a new 150 amp alternator in the Camaro to replace the 94 amp 12SI. The alternator manufacturer recommends adding a new 4 AWG wire going from the alternator's battery charging post directly to the battery. When I looked at a diagram of the existing wiring, one of the original wires now seems to concern me with this approach. See the diagram below.

Currently, there is a wire running from the horn relay, across the front of the radiator core support, to another junction block next to the battery. The battery charging circuit is completed by a lead wire running from this junction block to the battery. With the new recommended charging wiring going directly to the battery, the original charging wire tying the horn relay and junction block together seems to no longer be needed. Since I'm not an electrical engineer, I don't know what effect this new wire will have "closing the loop" so to speak. I don't even want to start the car until someone can help me wrap my head around this. Thanks in advance.