This is a valid point in that yes, you do hear the harmonies emphasised in these songs after the lead vocal has finished except for adlibbing.
I would add though that in my opinion a couple of songs where the vocal ad libs are overemphasised & go on for too long so that they overshadow the harmonies. These songs, as I mentioned before, are The Long Run, Hole In The World & I'm afraid, Take It To The Limit.