Weathermatic SmartLink Controller Wiring Question

I have just purchased Rachio 3 and planning to replace a Weathermatic SmartLink system.

Today I was turning on the old system to test out, in preparation for Rachio 3, and taking photos of the current wiring. I noticed that there are a few wires coming off the PVC pipe but was not connected.

One is green wire, supposedly the ground. The end of this wire is not even stripped. So I assume it is not necessary to connect it.

There are two other red wires (all other zone wires are in red color), which had ends stripped but were not connected to the zones. What could be those wires for? The controller has 8 zones, 7 in use. Maybe because there is not enough zones in the controller the installer just not connect them? Any other possible explanations?

Further information: The 7th zone runs a soaker line in the landscaping. When I tested that zone, only half of the house’s landscaping’s soaker line is watering. I am not sure whether there are soaker lines under other part of the house. Or maybe there are soaker lines buried but not connected to the controller.

My new Rachio 3 has 12 zones (Costco model). I am thinking just treat those two wires as zone wires and connect them to see what could turn out. Any danger in doing so?

Any help is greatly appreciated!