Actual electrical (ok, electronics) engineer here. Our team, including myself, has the capability to design stuff like the MacBook power supplies, though that's not our strength and we'd not be the best choice to do it. But we
can do it.
>Chargers are grounded to neutral.
JESUS FUCK NO NO NO NEVER NO DO NOT DO THIS EVER THIS IS LETHAL NO NO NO (stop emoji) (death emoji) (stop emoji)
So you can kind of get away with this in the US, where electricians generally know how to wire outlets, and get neutral versus hot correct. But they sometimes screw up. And when they screw up, if you're dumb enough to "ground to neutral", you get 120 V AC to earth on your chassis. THIS IS JUST WAITING TO KILL SOMEONE. PEOPLE CAN AND WILL DIE IF YOU DO THIS. (Accordingly, it's not permitted, and if you take this bullshit to a NRTL, they had better fail your ass.) In Europe it's even worse: electricians don't bother to distinguish hot and neutral, to the point where they insist on fusing both lines of everything that gets fused. So in Europe this is a 50% chance of getting something lethal when it's plugged in.
So, uh, in short: this had fucking well better not be what Apple did, and even if they tried it, NEVER DO IT YOURSELF because IT CAN AND WILL KILL.
(More likely they're just using isolation and allowing build up of stray charge instead of dumping it to earth like usual, because they didn't bring in the earth conductor. Which is annoying but not going to get anyone hurt.)