I think it was a preemptive attempt by Apple to avoid the current situation. They looked at the what was supported by 4th Amendment and designed a technical system that was the best compromise of no access and the ability to search for known images.

They would rather have maintained the status quo but thought they had hit on something that would work. Since they didn't need to do anything pulling the software was an easy fix to the controversy. The governments are the ones that are pushing this so let them take the heat.

Apple has a working solution and they can just wait and see what happens and react accordingly.