Unexpected Separation?

[Mutter]

2020 Ford Fusion PHEV
I had a slow leak in one of my tires so I went into the shop to have them find and repair it. No problem. After sitting there for a while the guy I had worked with said, "Hey man. Come take a look at this." He took me out to the garage where my Fusion was lifted and brought me underneath. ALL FOUR tires had significant tread separation on the inner sidewall with the back two having huge gaps in the sidewall!! I was stunned. I mentioned that I had never seen anything like that before and the technicians said he hadn't either. These weren't crap tires. I can't remember the exact model but they were very decent Pirelli models and while they did have some wear on them, they certainly weren't ready for replacement.

I ended up replacing all four tires. I didn't really have a choice.

 

I've been racking my brain about how this could happen and I was wondering if other Fusion Energi/PHEV owners had seen anything similar. Two things come to mind:

1) The car is just a normal Fusion (or maybe Fusion Hybrid) retrofitted with a huge battery in the trunk. The major separation was in the rear two tires that are supporting all of that, perhaps poorly accounted for, extra weight.

2) When the car is charging, it gets quite hot near the rear of the car (hence the current recall, etc.). Could all that heat be impacting the tires. Recall that the separation was completely on the inner sidewall of the tires. Again, this heat is focused near the rear of the vehicle (i.e. that rear tires).

I don't know. It's just odd. I'm not young and I've had a LOT of tires on vehicles over the years and I've never seen something like this. I guess it's possible that all four tires were just defective, but that's a pretty bad stretch of luck.

[jsamp]

I just replaced my tires today for the first time.  I bought it CPO with 43K miles and brand new tires.  I just cleared 110k miles last month so over 65k miles on a set of Michelin Energy Saver A/S (stock tire).  There was a 'wobble' sound at 25MPH in the left rear tire for the last 5k miles or so.  Could have been a tread issue but I never investigated knowing I was about to replace the tires.  Sure enough the sound went away with new tires.

[Mutter]

The lack of concurrence actually makes me feel better. I'm going to chalk this up to a one of those bizarre and never-explained situations that life throws at you every once in a while.