I personally never heard of it. I called Tire Rack just to get some information on the tire. They stated it was a new Tire available for purchase but Tire Rack didn't have any ratings on the tire as of 6/7/2016.
Toyo is a real, reputable tire company. What, exactly is your concern? Tire warranties are usually in a separate book. If you don't have any information, contact your dealer... But Tue warranties are useless Si why do you care? (I have never, ever been able to use a tie warranty even when I has tires down to their wear bars at 15k miles in 18 months. Considered wear and tear and nobody would do anything for me. Gave up after wasting hours trying to get some proration.. I don't buy Pirelli tires for this reason.)