If you're right, then they won't think it applies to them and so it won't hurt their feelings.
win/win.
How many can there be? Tapachula isn't such a big town so they were obvious as they assembled. The pic looks like southern Mexico, so they have a long way to go. 2000 miles of walking?
Trump should announce that they won't be allowed to cross the border and won't be granted asylum. If they're strong enough to march all that way, they're strong enough to make it back home. That will start to demoralize them. Will they want to cross the northern Mexico desert to be turned back?