When I first heard of this "virus" I ramped up my own cricket production to compensate. After much research I ended up with the same questions as you.
So, an experiment!!! Muhahahahaha
I have an extremely clinical and clean breeding operation so very few die from hatchling to adult. I put one colony aside and didn't keep it very well and neglected the cleaning and just kept throwing food and water in there. They all died. This is a small example to be sure but it leads me to blame poor husbandry at the cricket farms to be the cause.