[delib]

The concept is a bit confusingly named, but that doesn't make it "bogus".

(Period) life expectancy at birth summarizes the current health status of a population, nothing more, nothing less. It doesn't make a predictions about what happens in 2078.

[PaulHoule]

Yes, but it is rarely explained as what it is when it gets talked about. I think most people would assume that this is a prediction.