This extended downtime is contingency to allow the August 1 fork threat to be fully ameliorated. All funds are safe and service will be fully restored

Bitcoins aren't really very anonymous, you can make it time consuming to track you by tumbling, but not impossible if someone has the incentive to do so. I imagine it will be very hard for anyone to actually use those bitcoins without their identity being revealed at some point. At which point they will most assuredly be tortured by hired men to hand over their crypto. Whoever stole the money just made thousands of enemies, many of whom still have significant amounts of money and know how to access the dark web.