The security holes found will often affect current versions as well. Which just means more (and worse) black eyes.
Unless, of course, the internal review caught most of the holes that crackers may find. Which is a possibility so remote that it would take a complete idiot to believe it.
I don't think that upper echelons of Microsoft management are that stupid. If they are, then the companies that they beat should hang their heads in shame. Not only did you lose to monopolistic bastards, you lost to incompetent monopolistic bastards.
Cheers,
Ben