That's kind of a strange question. It would be a confirmed theory rather than a conspiracy theory if there were empirical evidence. I would say, though, in support of the theory: (1) this is how the ultra-wealthy have always behaved throughout history, to advance the interests of their own social class, to preserve and enhance their social inequality, and (2) I have a hard time trusting the motives of the people who have set up these foundations, because they've always been ruthless and greedy throughout their lives. Gates has never stopped accumulating personal wealth; his net worth is higher now than when he "retired" and claimed he was going to give most of his wealth away! Buffett has never stopped accumulating personal wealth either. It's a cop-out to claim that you're going to give everything away to charity, but only after you're dead. Moreover, your pledges are worthless when your dead, because your children who now control your money via the foundations may behave in ways that you didn't intend (which is often the way with children).

If you're going to give most of your wealth away to charity, and by that I mean to actual people who need the money, not to a "foundation", then give it away now, before you die. I do not trust Bill Gates one bit, not even one tiny bit. I don't even trust the foundations to do good. https://en.wikipedia.org/wiki/Bill_%26_Melinda_Gates_Foundat...

So you can say that my conspiracy theory is the most cynical interpretation of the situation, due to my cynicism about the billionaires themselves.