I just don't buy the whole battery swap thing. The battery is such a huge component of an electric vehicle that it is heavily constrained by the shape of the vehicle - or else the vehicle shape must be constrained by the battery. Can you really imagine the world's car manufacturers agreeing on a standard size, layout, architecture etc, removing all freedom to make a car longer, shorter, narrower, wider, ...
And that's just for cars, which don't have to worry over-much about aerodynamics. Now apply this thought to aircraft design. One, or maybe a handful, of standard batteries that will work for everything from 2-person helicopters to LSA trainers to commuter aircraft? And every FBO is going to have these on hand, so that when you fly your electric R22 or electric Caravan into Ailerona Muni, you can be sure they will have a suitable battery on hand and charged - just like you can be sure they will have Avgas or Jet A1 today?
Not to mention, battery technology is moving very fast (though nowhere near fast enough for the dream of electric aircraft to succeed any time soon). Standards don't work well when the technology is constantly changing. What happens when you arrive with a size X battery on board, but yours is a 500Ah Mk 3, and all they have is a 800 Ah Mk 5?
Electric cars may have a future (though personally I doubt it, once the hydrogen infrastructure is in place). I'm pretty sure that electric aircraft are a very long way off, if ever.