The V2H may not be available out of the gate with the Lightning. The standards to implement it have not been finalized and adopted. Ford could of course do their own thing, but I find that unlikely.
Implementing it on a vehicle is software and could be done OTA. The hard stuff is on your wall and the interconnect to your utility company is usually where it gets sticky.
they're building it into the wall unit. Shouldn't require too many special trips from the car, other than the software to push power back the other way through the wall unit.