At amsterdam, in particular, most of the time one has a very long taxi to get either to parking, or to the runway. In the 747, when heavy, the taxi distance can equate to very hot wheels, even without brake useage (the weight of the airplane on the wheels, during taxi, causes the wheel and brake assemblies to heat up). If the airplane is going to be turned around quickly, then anything that can be done to reduce brake temperatures is a plus.
One technique that's often used is to use minimum braking. Generally this is done with reverse, as landing in autobrakes will reduce the amount of brake useage when reverse is employed. The airplane only cares about the rate at which it slows down, and doesn't care what's slowing it down; autobrake settings reduce brake application if other means of slowing the aircraft down are employed.
Some pilots will land with autobrakes and shut them off once the spoilers are deployed and reversers are out, preferring to wait until late in the roll to apply brakes (assuming sufficient runway).
If the brakes aren't in use, then getting those nose down won't be of any benefit. Generally on landing, the ground spoilers deploy, killing lift and putting more weight on the wheels. Lowering the nosewheel to the runway also reduces lift and puts weight on the wheels, for more effective braking. If one isn't doing a lot of braking, but is instead relying on reverse and some aerodynamic braking, then this explains the rollout on the video.
In the case of no braking, any aerodynamic effect achieved from holding the nose off is beneficial, even if it's minimal. You can see in the video that the crew deploys spoilers immediately on touchdown (autospoilers), and then applies reverse, and rolls out in reverse with the nose off.
The hazard of doing so, of course, is that directional control is improved with the nosewheel on the ground, and reduced with it in the air. At higher speeds with ample aerodynamic authority for the rudder, this isn't a problem, but generally we try to get the nosewheel on the ground earlier. Deploying reversers with the nose in the air isn't a problem so long as everything deploys evenly and there's not a strong crosswind, and all the engines spool up evenly. If there's a directional problem or challenge, however, control authority is much better with the nosewheel on the ground, which is part of the reason that you're probably used to seeing it lowered earlier in the landing roll.