I've got it now! (he says with an echo to an empty auditorium)
Just as Zaphod_b said (above), the creation of the array was NOT an illegal instantiation of an object in the abstract class Employee - as much as it looks that way, it's not. I was misled by the existence of a constructor. It's in an abstract class (Employee) and it's illegal for an object to be instantiated in an abstract class. So the constructor, along with the array-creation statement, seemed contradictory to the claim that an object cannot be instantiated there.
In the end, the array was created to hold references to objects instantiated in other classes, descendant classes, for the sake of illustrating polymorphism and the subsequent use of abstract classes and methods.
If this were not my own post, I would surely be asleep by now.
Thanks again for your in-depth explanation, Zaphod_b! And thank you to all the empty seats out there, for listening.