In this new global age, the International Date Line interferes somewhat with nailing down specific dates. In some parts of the world, it's already April 1.
I guess it's because in Australia it has been April 1st for 3 hours already.
Google Maps still has a lot of development work done in Australia. So it doesn't surprise me that the april fool launched 'early' in their timezone.
This is the April Fools stuff I don't mind. Not a "prank" or fake story, just a cool thing you might not be able to justify at any other time.
A lot of the maps team is in Japan, so the maps April Fools stuff tends to launch at midnight GMT+9