Can't agree that that there is a shelf life on blueberry, although I've only been making blueberry wine for 4 1/6 years now - none of my have aged out.
Each variety of fruit wine is different and depending on how you prepare it that might change matters as well. Some folks on here have had wines that they declared undrinkable at 2 years but suddenly after 3 years they turned the corner.
I've had a few that I felt were great at 6 months (Pineapple/Mango) and Plum (From a wine base) BUT normally I try to wait no less than 9 months before bottling. Virtually ALL my fruit wines get some degree of back-sweetening. Therefore if there is any problem with an aged out wine, it's more likely to come from say a sorbate that ages out, not the wine itself. BUT your experiences may differ. High Storage temps, Rapid and many changes in temps, exposure to light etc all sorts of things can affect a wines taste over time.
I do have a couple of bottles of Strawberry and apricot that are 3 1/2 years old and I can tolerate them but they have never been to my liking.
MANY factors are involved in how a wine stores and as I posted on another thread - In Wine Making , Hard fast rules are Hard to come by.