I've noticed the same trend with SWEs tbh. Many new grads from the top schools have parents who were SWEs or SWE adjaent
e.g. my buddy whose grandad was a lineman and later a telephone company manager, and dad was a mechanical engineer, and he ended up SRE / devops
So the richest, most prestigious schools where legacy admissions are a gateway to the upper classes, will keep the policy.
Affirmative action was gutted by SCOTUS when Biden was president. Not that it was popular before. California of all places rejected it by 56-44 margin in 2020.