The 50-100 (really 140-450 points) is from Princeton study on Asian SAT stats for admission in private colleges vs other races. Apologies for wall of text.

Alternate explanation is that particularly sneaky elite admissions boards have learned to coordinate to devalue SAT scores for Asians, they'd rather engineer their mean Asian SAT score around something not embarrassingly high as cover for other cohorts, especially legacy which AFAIK doesn't need AA skew, since they're... legacy. AA primarily brings down average scores of non-legacy, and in this case make legacy look better, like average at Harvard for non asian & non white is 1450 according to your link, which is low considering 1500+ scores is 9th percentile for 223k Asian takers [0&1]. This is slightly conspiratorial, but also essentially what started the anti-AA case was when an Asian applicant with 1590 got rejected from multiple elite colleges, and the case essentially revealed high scores make Asians seem like bland test takers with bad personality even though personality assessment showed otherwise. Asian scores are high enough to break Harvard's argument not just for AA but IMO legacy as well.

Some other considerations, with respect to Harvard, according to latest admission data, @28% asian enrollment out of 2000 for class of 26, that's about 550 asians (previously this was ~20%). The real question the Harvard admissions stats don't show is how many Asians with 1550+ scores are being rejected due to "personality". If you look SAT score distribution [0], Asians are the only group where perfect math score is NOT 99+ percentile rank but "only" 95, and on ERW Asians 750+ score is 95 percentile vs other groups where it's 99+ except whites / multi racial at 98. Meaning Asians have disproportionate candidates with most perfect math and close to perfect ERW scores of all groups. Asians also total score outlier in that 1500+ is "only'' 91 percentile vs 98 to 99+ for everyone else. Collegeboard also has info that about 223k Asians (out of 2.2M takers) took SATs (2020 data [1]), so there's ~20k Asians with 1500+ scores (9th percentile). If extrapolated from 98th percentile of over 1500+ scores from 2.2M takers, that's ~44k total pool over 1500+ candidates of which 45% are Asians. 45% Asian is also in line with UCs where prop 209 banned AA and led to 40+% asian campuses.

Question is how many of 1550+ ones are Asians, keeping in mind ~7000 Asians have perfect math scores. My gut feeling is there are many 1550+ Asians being rejected by elites for skewing scores too high to keep legacy admissions charade going, especially at Harvard, because any Asian who scores that high, which rough napkin math is multiple size of their annual enrollment, would have an application to Harvard and eager to accept. Hence the narrative harvard stats paints via omission even by their student journalists, is that legacy does better non-legacy whose down by affirmative action, and legacy slightly worse than Asian Americans, when reality is Asian Americans have more than enough candidates to saturate scores above legacy and affirmative actions so their aggregate score has to be kept down through admission shenanigans.

[0] https://satsuite.collegeboard.org/media/pdf/sat-percentile-r...
[1] https://i.redd.it/l6hb0eq4k5271.jpg