verb tense from Magoosh video

Dear zoezhuyan,

How are you? I'm happy to respond.

Some of what I say in the Magoosh SC is specifically for non-native speakers and that material really irrelevant for the native speakers. Other things I say are directed toward the native speakers and thus is completely irrelevant to the non-native speakers.

The comment about which you are asking is one of the latter. I understand that this recommendation may sound completely bizarre to a non-native speaker who is learning the official rules of English grammar. Clearly, there would be no logical reason to make this mistake.

In American casual colloquial English, this is widely-used mistake pattern. There NEVER is a correct way to use the present progressive to talk about the future. It is ALWAYS WRONG, in well-spoken English and on the GMAT. Nevertheless, it is one of many widely used mistakes that one hears native speakers of English using every day.
Tomorrow, I am visiting my aunt.
Next year, the team is playing in a new stadium.
Both of those sentence are 100% incorrect and are quite typical of what less well-spoken Americans would say. Because it's a widely used mistake pattern, I have seen the GMAT use it a few times as an incorrect answer choice---such a mistake pattern is designed to ensnare native speakers with a poor grasp of grammar; it is not designed to catch non-native speakers, who are much more likely to avoid that particular mistake.

Non-native students make mistakes because there are subtleties of language that they haven't learned yet. Native students who are not well educated or well-spoken make a completely different category of mistakes, because these people have never troubled themselves to learn how to speak the language properly. At least the non-native speakers tend to appreciate that they have more to learn. The native speakers who think the poor grammar they use is fine have absolutely no idea how far from the ideal they are. To that extent, the non-native speakers have something of an advantage.

Does all this make sense, my friend?
Mike