Must the entire class hierarchy be recompiled if a virtual or non-virtual function is added to the base class in C++?

I am trying to learn how sensitive the vtable of a class is in C++ and, for that, I need to know whether recompilation of the entire class hierarchy is necessary for the 3 change-scenarios I list below. First, here is my class hierarchy:

class A {
   public:
   virtual void method1() = 0;
   virtual void method2() = 0;
};

class B : public A {
    public:
    virtual void method1() {};
    virtual void method2() {};
};

class C : public A {
    public:
    virtual void method1() {};
    virtual void method2() {};
};

Here are my scenarios:

1. A non-virtual method is added to the base class A:

   void method3() {};
   
   

2. A virtual method with a body is added to the base class A:

   virtual void method3() {};
   
   

3. A purely virtual method is added to the base class A:

   virtual void method3() = 0;
   
   

In scenario-1, no change to the vtable is made. Is it still required for B and C to be recompiled?

In scenario-2, will the vtable be reconstructed for base A, and consequently for B, and C?

I know scenario-3 will force classes B and C to provide implementations for the new method. So, the entire hierarchy must be recompiled.