Working hours are working hours. When else are you going to call, and where else would you be at the time ?
I've not heard of this call back thing before. No it does sound an abandonment of the rights of the patient to respect & privacy, no thought given as to how they'd feel. Maybe you can get partial relief by giving a mobile number and then walking outside when the call comes in ? But hey, no one should be deciding on whether you need an appointment prior to an examination anyway. That's what the appointment is for, to work out the situation. Sounds like yet another deterioration on how society does things. No doubt it'll be pushed as "the norm" soon enough, in order to belittle those who dare protest.