"There is no plan to ease the entry into the AI era," Gates writes in an essay.
Buffett was one of only three trustees at the foundation -- the other two being Bill and Melinda Gates, who are in the process of divorcing.
"Our focus on our culture, our diversity, our inclusion, in particular, the everyday experience of our people is super important, it's a huge priority," Microsoft CEO Satya Nadella said.
Bill and Melinda Gates have been in the process of getting divorced for two years, according to The Wall Street Journal, and one factor was revelations that Bill had spent time with Jeffrey Epstein.
Despite the loss, Musk is remains the second-richest person on the planet and $21 billion ahead of Microsoft founder Bill Gates, according to Bloomberg's Billionaire's Index.
Gates talked politics, missed opportunities, and his hope for vaccines, treatments and improved testing.