As the others have implied, underinflation is one of the primary causes of tread separation. An under-inflated tire builds up a lot of heat and the heat causes the plies to separate a bit, resulting in more heat and... you get the picture. It is not at all unusual to take delivery of an RV and have the tires improperly inflated for the load. You need to weigh the rig, preferably at each corner but at least front & rear axles to find the load on each and then inflate the tire according to the tire manufacturer's load tables. It is unlikely the dealer did this and it would have changed after you loaded your gear in the coach anyway.
Although the Goodyears have an excellent rep, I wouldn't rule out a manufacturing defect either. Difficult to prove, though and any dealer or factory rep is going to be very suspicious about the tire loading and inflation.
Former owner of 2004 American Tradition and several other RVs
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC