There has been no mention why this has happened but Konami has sent out a memo stating that all the official Japanese launch parties for Metal Gear Solid 4 have been cancelled.

The bad Google translation goes as follows

“Dear Customers:
Notice of Event Cancellation

We are deeply grateful for all the special attention and fan-base that our company have been receiving.

Due to various reasons, the “METAL GEAR SOLID 4 GUNS OF THE PATRIOTS” launch memorial event which was to be held on June 12 at 3 different locations within the Tokyo area, has been canceled.

We apologize to the customers who were looking forward to this event, and also ask for your understanding.

-June 10, Konami Digital Entertainment Corp.”

So why was it cancelled? My guess is that enough stores have signalled that they would be having a midnight launch and Konami could no longer justify the cost of these parties to the bean counters…

Source: Konami.jp