I'm not sure why. But if I wanted Van Halen sound copy without buying expencive replicas. I would go with Norton on bridge. XD
Edit:
But it makes sence for him to play Super Distortion for 1st album. Since in that time pickup market was limited.
But today you can have tons of stuff to replicate sound without spending 200$ on pickup.
If I wanted something like that, Norton or Satriani range would be my starting point.
But again, makes sence for him to play Super D. in that time.
Since choice was pretty much; Gibson Classic 57 or DiMarzio Super D. xD
And we all know that Classic 57 would not work for that.
But today. U have Norton, U have Satriani range.