Black Screen of Death

The outer display on my Fold 4 suddenly stopped working, went to Samsung service center and they said it needs replacement without even verifying if it is just disconnected or actually broken. Anyway few days later they called me and said in order to fix the outer display they also need to replace the inner display (and want me to pay for both), so my question is, is it true that the outer display cannot be replaced without replacing the inner display?