I thought this was common practice in US universities, in the form of so called 'legacy admissions' [1]?
Many schools give a general boost for legacy, but it is not always so tit-for-tat as the transactions that occurred here with Cal. They'll often have a different non-legacy pipeline for large donor -> admission.
For instance, at Harvard, there is the legacy SCEA process, but there is also the "z-list" process which is the more direct "children of billionaires" route.
Those would simply be fraud considerations in a private institution that charges an application fee.
Of course, a private institution also has Equal Protection / (Substantive) Due Process considerations at play as to what the published factors and criteria can be, as well as (Procedural) Due Process considerations as to whether it actually follows them.
I was in graduate school when I first learned that writing good grant proposals (and other skills related to acquiring large quantities of money) was arguably more valuable than doing good science.
... I'm more surprised it was only 64 kids.
The real number is likely much, much higher, and they say so.