Just today, 12/14/2016, I had new Michelin tires installed on my SUV. The production dates on 3 of them are the 32nd week of 2013, and the 4th tire was produced in the 37th week, of 2016. Should I be concerned?
It depends on your use case and how the tires were stored.
Tires, like a lot of other rubber things - I'm looking at you, Garage Queen Corvette owner - degrade over time. How fast and how badly depends on temperature, humidity and a lot of other things.
Serious autocrossers and road racers will tell you that they bag or shrink-wrap their tires when off-season (or, if they have more money, buy a new set frequently) to keep them from drying out and hardening. (Soft tires get better traction, but also wear out faster.)
In all honesty, on an SUV, you shouldn't really see much of an effect. Are the tires noisy? Is the ride rougher than it was before? Those could be a symptom of rot or hardening due to improper storage.
Given the level of (in)competence I've experienced at Every Tire Change Place Ever, I'd demand replacements. Sure, your tires are going to start decaying on your vehicle; however, that should start when you get them, not when Discount Tire threw them on the pile behind the non-climate-controlled warehouse.