Heinlein imagined the Howard Foundation as a group founded by a millionaire dying of "old age" in mid-life; founded to encourage long lived people to have children together using financial incentives with the goal of breeding extra long-lived humans.
Our world has many billionaires, typically older rather than younger people ( Forbes list - few under 50 ); middle aged Bill Gates has donated his fortune to normal kinds of charity, elder Warren Buffett has as well, youthful Mark Zuckerberg has pledged his too, all healthy. Steve Jobs is worth over a billion dollars and has been criticised for his lack of public philanthropy, he's also CEO of a company with $60 billion in reserve, and suffering serious health problems.
In short, we live in a world where there are rich people, and where you hear the idea of "rich old white men spending a lot on medical treatments to benefit rich old white men" but at the same time, Aubrey De Gray style serious discussion of longevity is rare and much medical spending goes on alleviating and curing the problems of old age rather than avoiding them.
Sergey Brin has donated $50 million towards Parkinson's research based on DNA tests showing he has a 50% chance of getting it, yet at the moment he has a much higher probability of getting old-age and a net worth of $10-15 billion.
Is our world one where something analagous to the Howard Foundation will appear? Let's pull some numbers from thin air and say that means someone dying and leaving pretty much all of their estate of more than $200 million to fund longevity research/treatment in some way. If so, it might be something done in private that we would not hear of, so what would be indicators that it might be about to happen, or might have happened already? And if an ill middle aged technology billionaire with change-the-world drive doesn't do it, then who?
(I consider significant increases in lifespan (100 healthy years, 150 total years, or more) nearly inevitable at some nonspecific time in the future, given a world where humans continue to develop technology improvements, remain primarily biological, and avert or avoid existential risks and government restrictions on it. I also consider that dying and leaving money to The Gates Foundation is a good cause arguably much better than longevity research, wheras dying and leaving hundreds of millions to heirs / dogs homes / art / etc. is not).