That pin is supposed to use data signals of less than two volts. The nyko charger uses nine volts. The switch has no over-voltage protection on that pin, and breaks at more than six volts.
The part about a slightly thinner plug isn't relevant at all.
The only outliers are moronic implementations like Nintendo, where they ask for capabilities, receive the charger capabilities and then just start pulling power at hardcoded levels even if the charger doesn't specify it supports those power levels. But there's nothing you can do against that - you even with different port shape, a broken implementation can still fry your device.
I infer your point: the shape of the connector in theory is decoupled from risks in power delivery... but in reality the prevalence of cheap knockoffs and "moronic implementations" makes me question the wisdom of combining [potentially dangerous levels of] power delivery with data transfer.