At least for me, it’s not about bitterness or jealousy. Good for this kid. He seems to have a bright future. It’s rather about the behavior in publishing his success.
My kid was admitted to several very selective universities. His success in the admission process far exceeded that of his classmates. He kept it very quiet. Word got out, but he stayed humble and didn’t brag. I was proud of him, but was keenly aware that other parents would not appreciate it if I crowed. Idk, I just wasn’t raised that way.