For someone who says "use your brain", you sure could use some reading comprehension lessons.
1. "Evidence" refers to "Apple's motivation": did they do this because they genuinely want to help the environment, or because they're cutting costs and increasing profits? Everyone knows it's the latter, and more power to them, but don't try to lie to people, they can see right through it. Let marketing figure out a way to sell this cost-cutting measure as a benefit to the consumer. Something along the lines of "we discovered that 90% (or whatever) of our users already have a charger, so we're giving you the option of buying one or not, and you pay less if you don't".
2. Leaving that aside for a moment, assume everyone would buy new chargers. In that case, it would be worse for the environment, as you would be producing two boxes instead of one. Therefore, there is at least one situation in which it is worse for the environment. Thus, it's not automatically beneficial for the environment as you claim. Therefore, it's up to you to prove that enough people will forego buying a new charger that it is a net win for the environment. But of course, there's no need to prove that, because as mentioned in point 1, the evidence is for Apple's motivation, not for the environmental benefits.