That being said, even if da Vinci had absolute certainty that his viewpoint was correct, that heavier-than-air flying machines were a factual inevitability... what could da Vinci have done to capitalize on this knowledge? Other than draw some diagrams and hope future generations pick it up, but in his own contemporary timeframe, this knowledge of the inevitable future would still be generally useless to him. It would not affect his daily life, it likely would not change a single decision that he would make otherwise.
Likewise, let's say you're right, that conquering death is an inevitably solvable engineering problem. So what would you do with that knowledge, right now? Of the cases called out in the article, of people who could not live off of ECMO, how does having this knowledge of inevitable immortality that's coming 100s of years later, how would that change the decision-making rubric today for those patients or whether those ECMO machines are better used on someone else?
I venture to say that, even if you knew with absolute certainty that engineered-immortality would be achieved by a known future date, say 200 years from now (though it took ~400 years between da Vinci and heavier-than-air flight)... IMHO it shouldn't make any difference at all to the present-day decisions of how those ECMO patients should be treated today. Only if you knew the date of pending immortality was let's say, <10 years away, would you make some kind of drastic push to try and keep everyone alive barely long enough to benefit from that breakthrough.
... In fact, I vaguely remember reading a short story about this very conceit, of generations of humans in a fictional setting, working towards immortality, and how at a certain point, they reached a stage of awareness that, achieving immortality was likely going to happen soon in the next generation, so what would they do with that "last generation" of humans to ever need to face death? How would people feel, how would they react, if they knew that they were just a little bit too early to benefit from the breakthrough that might come 20 years from now? Sadly can't recall what that story was called or any more details that would make it easier to search for.