Kids away at college will just get their own accounts now. Compared to the cost of college with room and board, a monthly Netflix subscription is nothing, especially with the cheap ad-supported tier. Kids away at college do things like eat at restaurants and buy clothes which require money too, and if that money's coming from parents then so will a separate Netflix account.
It's not like it's some great American tradition that kids at college use their parents' streaming account. Nor did kids ever start getting their own Netflix subscription after graduating. If they were using it during college, they would continue after college, because why wouldn't they?
In other words, being at college doesn't have much of anything to do with anything.