If this was ever done (we'd have to get a little system coded up for it first) I think a cool way to do it would be to have loyalty badges - which is a bit different from birthday gifts but still similar as an annual thing. I'm imagining them similar to the armbands that the gms wear but you'd get one each year that you are a member of the game. They'd be non transferable but they'd get more and more illustrious each year so that you have a neat way to indicate your seniority.
Whether you take to that or not really depends on what the underlying purpose of your suggestion is. If you want to effectively reward being around in the game for longer stretches of time then it's good. If you want that but are worried more about just obtaining economic assets then it probably doesn't appeal to you.