Hollywood kids need their own separate category. They're living in an alternate realty that other well-off people aren't, one where bank accounts and notoriety supersede the traditional classist criteria of education/upbringing, family, networks, etc.
The more "old money", multi-gen African Americans of upper-middle+ backgrounds have networks, organizations and traditions that provide their children with exposure to other people who share their SES background that are also black. So even if their kid is the only black student in AP English they can hang out on the weekend with kids that share that experience and they're never completely isolated in a lily white existence.
Black folks with serious money but didn't grow up in that kind of situation, don't share a background or know people from boarding school, frats, prof orgs etc are probably more isolated. Some dr who is a fifth generation Morehouse to Meharry graduate, with a house on The Oval, and sends his children to Choate and Philips Exeter (or any east coast boarding schools and Country Days to an extent) is not going to introduce his daughter to a kid whose father is a functional illiterate with baby mama drama and a flock of birds and grandfather/great uncle are beyond street. It just is what it is.
Other well off black folk with different roots run into issues with their kids being isolated because they themselves don't have the same identity and sense of community, plus natural networks and communities that many Aframs have.
You got a lot of people that don't want to make their special little snowflakes take part in organizations and activities where they'd natural meet/befriend other blacks. Or don't like certain groups because they seem too "bourgeois" or they don't like race based organizations and making their kids feel racialized or different from their school buddies. But then sit around looking perplexed when their kid comes out their neck about 'those other kind of black people', feeling like a white kid in brown skin and wants to join SAE
, thinks we'd be post racial if blacks could just stop talking about race, their daughters never have prom dates (black girls just go as a group)/sons never have black (or even non-white) girlfriends and they never get a single solitary black grandchild.
At least know what you're going into and not sitting around dumbfounded that your child who was always the one raisin floating in the bowl of cornflakes grows up to have only white social networks, white educational and professional contacts, memberships in predominantly white organizations and activities, talks/dresses/acts like they have a yardstick impaled in their lower digestive tract, lives in only the whitest suburban enclaves, lives an excessively white bread existence and only ever has white lovers/partners/spouses.
They need to decide if having a whitewashed child is something that'll bother them before hand and create more experiences and opportunities to diversify their life but don't wait and get irrationally pissed at their offspring for being exactly like one would expect given their background.