I think they'd tell me that they were implementing an immunization program if they were going to.
I told them that we are in the process of building a varied poultry flock, and that we'd be ordering thousands of chicks, ducklings, poults, etc, over the next year, and that we needed to develop supplier relationships to ensure that we got healthy stock. If they were going to change this, then they'd have told me - you don't just whistle repeat customers away unless you can't satisfy them. They could have informed me of changes without admitting fault - corporations are experts at that.
You see, I know, and they know, that this did originate from them. They choose not to acknowledge it, and they choose to let it sweep through their flocks.
It won't hurt their flocks from their perspective (because the immune compromise in their adult flocks will only be minor - enough to compromise their ability to pass immunity to their chicks, and to make it a little more likely that they'll contract some diseases, but not enough to affect significant mortality) - it will only hurt their customers. Their chickens will keep on laying, they'll keep on hatching out eggs, and shipping out chicks. The chicks won't start dying until they are in someone else's care, where they can blame it on something else.
While they do supply some broiler and layer houses, a large body of their customers are people like me - ordering chicks in smaller batches. Customers like that tend to think they had bad luck and not order again, or they think maybe the feed wasn't right, or something. They almost never think to look and see whether a contagious disease is sweeping through their flock. They usually don't have the numbers I did to observe and draw statistics and patterns from.
I think they are stupid. Because this WILL go through all of their layer houses, and it will infect all of their brooder houses. Eventually they will do something about it, but not until it has harmed untold numbers of small farmers and backyard chicken raisers.
I've already found other complaints online that the chicks from this company "didn't do well", died in large numbers, only a few survived, and those seemed very disease prone. So it is out there in chicks other than just ours.