I agree with you and think this claim needs a lot more evidence. In my university we have been providing remedial math classes for freshman students for a long time. They must pass these before taking regular classes that have math prerequisites.
I had to take a math placement test which was exactly "do you need to take remedial math?" in test form, passing the test was a prereq for a large swath of math/science/engineering classes
I had to take a math placement test which was exactly "do you need to take remedial math?" in test form, passing the test was a prereq for a large swath of math/science/engineering classes