"class-neutral" sounds like code-word for "the most direct measure of competency doesn't serve our agenda, so we will throw it out". Should colleges find people who have integrity, honesty, grit and determination, commitment to ideals? Sure, but I'm not sure that is what this is, because they wouldn't need to use "class-neutral" in that case. Talent at mathematics is class neutral, though prior training for it might not be.

If you want to raise a generation of mathematicians, scientists, and engineers, then "higher education" is for continuing the education they have already received and adding to it. Parents from different classes give their children different opportunities and levels of education, fact of life, higher education is for research and extending human knowledge beyond what normal institutions do, some classes may not be at that level, and that is okay, they should receive as much education as possible, but not at the expense of driving the state of the art. If you want to find those who are prodigies at mathematics, test their skill at that and hone their gift, regardless of what class they are.