Agreements not to poach are illegal. In fact, Apple itself was hit by a suit by the US Department of Justice over that: https://en.wikipedia.org/wiki/High-Tech_Employee_Antitrust_L...

The suit you are referencing was an agreement between major tech companies not to poach/recruit from each other.

The issue discussed here is an employee agreement that prohibits former employees from poaching current employees.

The text that Apple signed prohibited them from: "attempting to enter into, entering into, maintaining or enforcing any agreement with any other person to in any way refrain from, requesting that any person in any way refrain from, or pressuring any person in any way to refrain from soliciting, cold calling, recruiting, or otherwise competing for employees of the other person".

I don't see how it doesn't fit this case.

And this is more egregious (in Apple's perception, anyway): current employees poaching current employees.