I would imagine they knew about this a while ago, but still had to get it GM by at least a week (maybe more) before shipping date, to be packaged and sent out. In this case, they have since had two more weeks to work on it since they sent off 5.0 GM, and now send out an update to fix it.
Sure, ideally, it would have made it in there. But not all projects meet deadlines, so having this come out so soon is a good thing IMO.