Let's put it this way: in reality, how is Apple ever going to know what charger you used? Obviously it can't.
So in practice, which is all that matters, it can never void your warranty.
And let's keep in mind, the entire purpose of a standard USB-C port is that you can use any charger. Otherwise Apple would use a proprietary connector on its charger, which it has never done.
So let's just stay in the realm of common sense here, OK? :) No need to be demanding whether someone is a lawyer, sheesh.
So in practice, which is all that matters, it can never void your warranty.
And let's keep in mind, the entire purpose of a standard USB-C port is that you can use any charger. Otherwise Apple would use a proprietary connector on its charger, which it has never done.
So let's just stay in the realm of common sense here, OK? :) No need to be demanding whether someone is a lawyer, sheesh.