No. It’s not unfair.
Like all of us, Brian is entitled to make donations to any cause that strikes his fancy and he must not be judged for doing so. We all have different causes to which we want to donate; what those causes are and how much one elects to give is no one else’s business. I repeat: no matter how wealthy he is, what Brian does with his money is none of your business.
You are really comparing apples and oranges. Brian gave an educational boon to his nieces and nephews. You are apparently upset that he didn’t give a boon to you. You would have more cause to feel slighted if you had children and he declined to make a similar gift to your children but your children are nonexistent.
Children, and people with children, routinely receive benefits single adults do not. College professors often get reduced or free tuition for their own children (whether they have one or 7 kids) which can amount to more than $100,000 but a childless professor does not get this benefit and cannot even transfer it to anyone such as his own niece or nephew.
Years ago Warren Buffett’s (second richest man in America) daughter asked him for money to buy a house. He told her “No. Go to the bank, borrow the money, and I will cosign for you.” At the time of his daughter’s request Buffett was already a billionaire. Was he being, as you put it, “unfair”? No. He was teaching his daughter a lesson. You need a similar education.
At the heart of your complaint lies a small sense of entitlement. You feel entitled to Brian’s largess. You are not. Strange as it may sound, it would be immoral of you to hold anything against him because he has not yet shared any of his wealth with you.
As a personal choice, I would be more generous with my single childless sibling but not out of any sense of “fairness.”
By the way if you feel as if you need Brian’s help why don’t you ask for it directly?