You're over thinking this
It doesn't matter if it's AC or DC, thinking about electrons moving a specific way doesn't really help you at all (and just causes confusion).
Think simple! - a 6v battery, a 6v bulb, and two pieces of wire.
Connect one piece of wire from negative of the battery to the bulb, and the other from positive to the bulb - the bulb lights OK? - a normal circuit.
Now get a third piece of wire, and connect the negative wire to earth - the bulb still lights, nothing has changed, yet the negative of the battery is now 'neutral, and the positive is now 'live'.
Remove the third wire from negative and connect it to positive instead - yet again the bulb still lights, again nothing has changed, yet positive is now 'neutral', and negative is 'live'.
The basic fact is that everything you measure is 'relative' to something else (essentially where you stick the other end of your meter) - so if you connect your meter negative lead to the negative of the battery, then the positive of the battery will read positive regardless of where you connect an earth wire. However, if you connect the meter negative to ground, then the battery polarity will change depending which side you earth, because you're now measuring relative to earth, and not to a specific side of the battery.
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ONLY reason live and neutral exist at all is because the neutral is earthed, the two terms are 'relative' to earth, nothing else - exactly as with the battery/bulb example. As a service engineer I use isolation transformers on the benches at work, this breaks the neutral/earth connection (for safety reasons), giving two simple mains wires, neither of which is live or neutral as they aren't referenced to earth at all.