I think this ultimately drives your opinion on his decision. My parents took a second mortgage and dipped prematurely into their retirement accounts so it would be nothing for me to give them 500k. On the other hand if they just did the bare minimum and didn't do anything extra for me I probably would keep all the money for myself
Absolutely. I value my mother for making the moves that would benefit me in the future. One day I'll be able to do the same for my own, if possible.
And your parents sound like really awesome people! Cherish them forever!