Air ground logic
I imagine its to give air/ground logic to the various systems.... Especially spoilers. Even if both LGCIUs fail , you have " Independent downlock logic " to the "green lights " on the panel above the lever...
Anytime the EMER Gen is selected , it Latches on as power source to ESS busses til maintainence action.
Emer gen , powered by the Green system, be it Eng driven pumps or the Rat...
Landing Gear , biggest user on Green system.... Manual extension to prevent a "shock" to the Green system and possible interruption to Elec power generation.