Life Expectancy is going up. In general. But what really matters isn’t the general but the specifics. I know it’s hard to work through maths and actual calculations, but it doesn’t help if you run your analysis off slogans.
US Life Expectancy is going up. But not as much “at retirement” as it is up “at birth” because all the improvements in infant mortality are irrelevant at retirement. Similarly, mortality improvements aren’t the same for all income bands. The detail matters when it comes to trillions of dollars of social security.