Right, we are talking about an electric car here. As of this moment, I can think of only one electric car that had anything more than a one-speed transmission. A select few Tesla Roadsters.
All other electric cars have a single speed clutchless continuous engagement gearbox. Because there is no torque converter or clutch packs or bands, there are no mechanical friction/slip components, hence nothing really to produce heat per se. Electric vehicle are always "in gear". Even the Neutral setting is "in gear". Reverse is just the motor running backwards. Yes, your electric vehicle is capable of freeway speeds in reverse, but there are electronic limiters.
EXCEPTION: The motor itself is a slip component and that does produce heat. However, coolant is pumped through the motor, so that handles the heat transfer out. Some electric cars, such as the Tesla Model 3 uses transmission fluid to cool the motor, and that fluid is cooled by a heat exchanger with coolant.
Probably any good quality oil with anti-wear additives could be used, not necessarily gear oil or Mercon LV. The temperature range of a electric vehicles gear box is much lower than an ICE, and there really is no need for an ICE type transmission cooler. Even a Tesla Model X with the towing package does not have an ICE type transmission cooler. Its not needed.
Now a person could argue that it would not hurt to have an ICE type cooler, and I agree, it would not hurt, but it sure would be a waste of money.
Ford probably specified Mercon LV for the FFE because it was the latest and greatest, it was of the best specification, and they could make more money off of it. And if it works ok, why bother with yet another lubricant for just 10,000 (?) cars?
An interesting contrast is the lubricant for the Fiat 500e gearbox. $40 gallon. Special European Shell proprietary oil. Special is because it is only available in Europe and it was developed especially for electric vehicle gearboxes. It is repackaged for Chrysler-Fiat. And it is a gearbox oil, not a transmission fluid.
Anybody who has replaced manual transmission fluid/oil will tell you that there is gear wear inside, and that metallic sludge sticking to the magnet could accelerate wear of softer metals if the magnet wasn't there. So it is a good idea to replace the gearbox fluid on ocassion. Because there are no softer metal synchros in the FFE gearbox, you could probably go 50k miles without concern. If you were towing with the vehicle, you might want to go every 20k or 30k. It depends on the quality of the metals, surface treatments, and hardening on the gears and bearings.