You know what, my sister's Accord V6 had similar cracks, however, hers was on the side of the seat and even thought her car's warranty had expired, Honda sent a representative out and looked at it and agreed it was a defect and replaced it.

For your seat, unfortunately, it is within where you would sit and it probably falls into the category of (wear and tear). I've had my TL for 4 years now and my seat is still brand new. Do you put conditioner on your seats? If not, you should definitely think about it.