No probably needs a couple more years. Writing the test itself is motivation to do well in HS math. If that no longer becomes a driver probably takes off the drive in other courses over a couple years. I bet without the SAT as a standardized test a lot of HS math courses are easier for the teacher because the quality can lapse.

Also some children who excel write their SATs sometimes 2-3 years before college and then re-write if need be.