If you agree with this decision on the grounds of supporting meritocracy, consider that the real travesty with regards to meritocracy in college admissions are legacy admissions.
How big a deal and how common is it in reality? "We have one fewer spots because we admitted the son of a donor" and "we won't accept you based on race" are different magnitude.
It has a surprisingly strong effect as schools get more prestigious / exclusive. At schools like Harvard, which have in incredibly low admission rate (something like 5% of qualified applicants get an offer, I think?), legacies get a massive bump.
https://www.nber.org/system/files/working_papers/w26316/w263... is analyzing the admissions data that got released from an earlier lawsuit against Harvard about Asian American admissions bias, and says that although being a legacy isn't as good as being a recruited athlete, it still gets you admitted at about 5x the rate of non-legacies.
If Harvard were to go from a race and legacy aware policy to a race and legacy blind policy, 20 minority students who would have been accepted would not for every legacy student that similarly would not. That is, racially discriminating is 20x times larger of an effect than legacy discrimination.
A typical class at Harvard has 2,500 student admits. Of those, 700 are black or Hispanic. If Harvard did away with legacy admissions, 25 additional Hispanic or black applicants would be admitted, so 725. However, if they did away with affirmative action, 450 would not be admitted, so you would be down to 275. Most of these 425 spots would go to Asian applicants and a chunk would go to white applicants.
It's the difference between "we're setting aside this slot specifically for you because of who your parents are" and "we're placing you in this competitive pool that will make up a certain percentage of the overall class."