With hundreds of thousands of deposits for the Tesla Model 3 I am coming around to the fact that an electric Mustang might be well received if executed correctly. It could also be a way to justify/finance the Mustang into the future including keeping around our beloved V8's or other ICE options.
To 'chain's point, many customers do not like the Auto Start/Stop feature appearing in many vehicles. Currently you can turn this off in Ford vehicles but if there comes a day when you can't I am not sure I would want a Mustang so equipped.
Currently all Ford hybrids have a standard 8 year 100K mile warranty on the battery. This type of support is used to make traditional buyers comfortable with the hybrid technology.