If I had to choose, I would spend the money towards a FordProtect extended warranty rather than a maintenance package.
As for the maintenance package, are new brake-pads or tires included? If so, it may be worth it.
Just my $.02:
From my understanding with regenerative braking, on Tesla's for example, brakes are lasting between 80,000 and 100,000 miles. I would assume the same with the MME.
I also thought most warranties specifically exclude "normal wear and tear items" such as brakes, windshield wiper blades, etc.
I also thought one of the main advantages of an EV vs. an ICE is the minimal cost of maintenance on an EV vs. an ICE.
As to an extended warranty, those usually cover mechanical parts, which do not exist on an EV.
Finally, the pricing of either a maintenance or extended warranty is based on an ICE - that is the pricing model. Keep in mind that Consumer Reports over many years has found that while these policies may give you "peace of mind" they rarely pay for themselves.
Personally I would wait until some time has passed and we actually know what service an EV is needed and I would expect the price of these warranties will drastically come down in price - if they even exist and/or are necessary.