Planes are nose heavy by design. The center of gravity is always ahead of the center of lift for stability. The elevators are trimmed to push the tail down for level flight.
Which way do you think the plane should go when at least a quarter of the weight of the plane is blown off the front of the plane with all four engines at takeoff thrust?
If I’m not mistaken the NTSB report said the plane continued to climb another 4,000 feet after the plane was blown apart. Another 4k feet? I’m not an aviator nor an aeronautical physicist but logically, that sounds impossible.