Petza914

Might be, but all you need is for this to happen once at 80 MPH on 7 year old tires to never go that long again. Pressure checked weekly and that morning, no prior damage (punctures, etc)

Zoefhaus

As you know it is impossible to determine on the basis of the picture whether this was caused purely by the tire being 7 years old (which I highly doubt).
There may be a tons of other reasons why this happened (external or related to the tire)

mcfisticuffs

If you're not tracking, save some money and throw some RE-11's on the back. Once those wear out (a year or two), replace with the Michelin PS4S. No sense swapping out the fronts if they're relatively new. The RE-11's may not be "as good" as the Michelin's, but for street driving they'll be fine.

Petza914

+1
Good advice and most economical recommendation

Hella-Buggin'

The RE-11's are a compromise tire. The sacrifice street ability for track ability. Don't get me wrong, I ride on AD08R's and they're similar. But if I wasn't tracking, I wouldn't run them.
Spend the few hundred bucks now to start off on a fresh slate with tires that suit your needs. The PS4S are fantastic street tires. They're quiet, great in the rain and comfortable.

kisik

R11s and AD08s are great tires for occasional track use before someone would move to R-compound. They represent some street use compromises where noise, 40F rain condition handling, and very stiff side walls would be a few.