Various ideas and accusations have been floated, but I think right now they are concentrating more on getting the fires controlled and will investigate likely causes later.
In some states fenders, and fender coverage over the tread of the tire, are required and so doing this may result in tickets if you plan on driving it on public roadways.
I used this for my fire extinguisher mount. I like that it bolts to the roll bar, keeping it well secured.
I keep thinking of a small extinguisher near the driver's seat to supplement it.
https://www.cooltechllc.com/2018-jeep-wrangler-jl/119-fire-extinguisher-mounting-kit.html