That is a pretty standard EA protection. Pretty amazing stuff. 2 normal tracks typically have a crosstalk area between them (typically on the half track). But the EA tracks are perfect from 4.75-6.50. And the protection scheme actually sweeps the head back and forth across the range WHILE reading the data.

They are actually just writing data to the concentric tracks, but just timing the steps between the tracks very carefully. When making a copy, you couldn't get the steps to sync up and so the timing for the steps would all be broken.

High end commercial copiers really didn't come into play until 1984-5.

I don't really think that this is the end of cracking. It is more of just the start of a new era of preservation. There is still a good amount of hardware out there like the CFFA3000 that doesn't support .WOZ images. Those will still require the cracked DSK files.