Yeah, sure, schools have always liked foreign “diversity”, because that has always been a draw for American students and their parents.
But the colleges I am familiar with now (and private high schools too), target foreign students (e.g., Chinese, Japanese, and wealthy Latin American) because their families will pay full load. Meanwhile, most American students do indeed get some sort of aid package—rather than paying the rack rate.
And they do not pay full load. I am familiar with it. They have "scholarships" set up for students from China. They also get preference as "teachers aides" which allows them to cut the tuition even further. The fact that the American students can't understand a word they say allows the college to claim that American students are dumb rather then they hired someone who can not speak English.
And unless you are talking sports scholarships very few American students get any aid unless you are talking about student loans. Those they do get. Calling that aid allows the college to fudge their numbers.