The dating on tyres(tires) is all about liability issues. A class action suit dreamed up and implemented by Big Tire companies' lawyers to absolve them of liabilities. Here in the USA, you cannot find a Tire Shop (automotive) willing to repair a tire more than 8 years old. It can have 10 miles or 10,000 miles on it; they won't touch it. You have to go to a tire shop that is not a corporate satellite store. Luckily, I live fairly close to the Mexican border, where tire shops and auto repair shops will try to fix anything.
Motorcycle tires: Many shops will no longer mount or repair your tire if you did not purchase it from them. It's not uncommon to see a charge of $50 to mount a tire, FFS! The small, independently owned tire and motorcycle repair shops are like Laverdas, a disappearing breed.
If you get a deal on a tire and want to store it, most manufacturers have guidelines on how to store tires indefinitely.
Wrap the tire in plastic wrap, multiple layers, and store it in a dark place at room temp < 75°F, or 21c, protect it from light, the big degrader.
Old tires stored incorrectly are friggin useless!