Ah perhaps I misunderstood you. You're arguing that more people are reaching our 'expiration date' rather than that date meaningfully changing. That definitely seems true, but I think there's some very clear causal factors in play there (which that article doesn't hit on). Both smoking and drinking are on the decline which is going to send life expectancy at older ages way up.
And the various observations the article does make have similarly straight forward explanations. For instance gains have not been seen to the same degree in Eastern Europe where alcoholism, especially in the windows of time considered, was chronic. It also mentions dramatic gains in Asia but yet again you had things like China's Great Leap Forward and the Indonesian Genocide in the time frame studied where you were seeing deaths by the tens of millions. It's akin to saying that global life expectancy increased dramatically after 1945, which is certainly true.
And the various observations the article does make have similarly straight forward explanations. For instance gains have not been seen to the same degree in Eastern Europe where alcoholism, especially in the windows of time considered, was chronic. It also mentions dramatic gains in Asia but yet again you had things like China's Great Leap Forward and the Indonesian Genocide in the time frame studied where you were seeing deaths by the tens of millions. It's akin to saying that global life expectancy increased dramatically after 1945, which is certainly true.