Today is the start of a new financial year so it would make sense that they reorganize today. I don't think it is an aprils fools joke because 1. Sony doesn't have that kind of culture and 2. You usually prank the general public, not your investors/stockholders, and certainly not through an official release via a corporate channel, on the start of a new financial year, lest it get mixed up with actual information released on the same day.
It would make sense too, considering now Sony is obviously focusing on the west, rather than Japan.