If there is a tolerance in the recipe for add pack, and if they brew up a big vat to bottle in 5 quart bottles for WM compared to 5.1 qt jugs for everyone else, one might notice a non-repeatable difference.
But their blend is going to be closer and more consistent from batch to batch than two seperate $20 VOAs from a mail order lab are going to show within one batch of the same stuff. In other words, a rounding error. And a WM blend would have just as good odds of being better than worse.
But they would not, could not make it cheezier, on purpose for WM. Not any more than Heinz would make worse catsup or Coke would make a different recipe soda. If they did they would be caught within the first month by this site and others.