BeerGraphs lists all the salient points in this case and tries to be nice about it.
But doesn’t everyone do this? Your Mercedes dealer isn’t required to tell you that you are buying a Chrysler. There’s no mention of Pepsico on your Quaker oats. P&G makes your Pringles, your Pampers, and your Pepto, which is appropriate. Corporations will fight anyone trying to make them be upfront about ownership and the brand mothership, down to the last penny in their pocket.
That last phrase is key. MillerCoors has a small army of lawyers on their side. Every piece of language on every brand they produce is carefully reviewed. The marketing of Blue Moon is certainly disingenuous, but so is almost all marketing.
I would argue too that the manufacturer of Blue Moon is common knowledge for anyone that knows enough to be intentionally purchasing “craft” beer. It would take mere seconds to google it, even.