Tempered glass is most fragile on the edges. A blow to the edge and it can shatter. The edges cannot have any contact with metal for instance and must be protected by means of rubber type material. I wonder if the issue has to do with how the glass in affixed to the frame and not allowing sufficient ”float” to the glass. I have not heard of spontaneous breakage where tempered is used in side glass that is frameless and vertical.
Glad to hear they’re covering it. It looks like your moonroof may have exploded outward like ours did, though plenty of glass fell inside. It was the pic that showed the outward explosion that got Mazda to cover it in our case (and a fantastic service advisor). Hard to tell on my phone, but looks like the same happened to your sunroof. First thing we did on the new sunroof was to get tint installed, that way if it happens again we don’t get a glass shower