If the representation part of type abstraction is declared private, then how does sub-classing violate encapsulation?

Here, I learned that sub-classing violates encapsulation:

it violates encapsulation, since the implementations of the superclass and subclass become tightly coupled

For instance, If we consider below Java syntax, a class has access to all the fields and methods of its super class provided they are not declared private.

class Person{
    private String name;
    String address;
    //methods of class Person
}

class Employee extends Person{
    float salary;
    private Employee immedateManager;
    private raiseSalary(float raise){...}
}

class Manager extends Employee{
    String department;

    void test(){
        name = "Fred";   //compiler error, could not break encapsulation
        salary = 70000.00f;
        address = "somewhere";
        immediateManager = "Slate"; //compiler error, could not break encapsulation
        raiseSalary(1234.0);    //compiler error, could not break encapsulation
    }
}

So, if the representation part of type abstraction (Java class) is declared private, then how does one understand before saying that, sub-classing violate encapsulation?