I was reading some product reviews for bike tires and came across a complaint from a customer who had received "new old stock" tires. Here's the relevant part of the review:
Feb 07, 2020
The two tires I received had the manufacture date stamp inside the tires of 2007 !!! THIRTEEN YEARS OLD RUBBER !!! ... In reading these pages you have seen reviews stating premature blow-outs, and greatly diminished tire wear. Both are symptoms of OLD rubber. ... It would be a good bet that this supplier bought-out some distributors ‘old stock’ for pennies-on-the-dollar. Let HIM eat his investment, not you. ... See the date stamp in the attached photo, both tires had the same stamp...
(source)
The review correctly states that other customers had complained about severe blowouts after relatively short miles, suggesting they too may have received tires too old to be reliable.
This seems plausible; but on the other hand I have some bikes with pretty old tires without problems. Of course riding conditions may also play a role.
In summary: is there a valid concern about otherwise new-condition tires that are 13 years old being unfit for use?
Note: I'm not asking for a judgement of this specific tire. It's just an example that prompted the question.