I have had discount tire replace 3 tires on cars in the past  with the replacement warranty.  It is a 100% free replacement, regardless of tire wear as long as it is (a) >3/32 tread left and (b) less than 3 years old.  It is NOT a prorated warranty and covers anything that renders the tire not repairable.
In once case I had 35 series tires on a car that hit a partially exposed water main cap at about 20 MPH.  popped one tire, big buldge on the other.  In a small town in the midwest.  Called Discount tire dealer where I bought the tires, they did a online check to see if anyone in nearby areas had the identical tire, nope,  so they gave me two options.
(a) they could overnight replacements to a local tire shop to replace mine.  problem was this was friday night I needed to leave on sunday, and Overnight really meant monday AM.
(b)  I could purchase 2 brand new 35 series Z rated tires of my choosing, have them installed and when I returned home they would cut me a check for the tires mounting and balancing etc. , and replace them with the tires I had originally on the car.
I did option (b),  I didn't need to even show them pictures or bring back the two blown tires,  they had an appointment set up for me when I returned, and handed me a check for the tires, replaced the tires and i was on my way.
I also got Maxxis TT tires from discount and for $15 each the warranty was a no brainer, sign me up.
I don't go for the warranty on my truck tires,  risk is low.  but low profile car tires it has paid off, and peace of mind with TT tires, well worth it.