I would say the answer to that is yes ,any practise will help
I know you are probably talking about faces but if you draw feet for example you will realise the toes are not straight and evenly spaced after looking at a few photos ,these sorts of things are little bits of memory that are stored same as differences in noses ,eyes ,planes ,angles, proportions........whatever all little bits of information stored in your memory bank which when you draw from imagination will be recalled after enough practice ......well thats my thoughts on it for what its worth
Practicing likeness on a drawing (aka drawing what you see, not what you think you see) helps train your brain to understand how the body is put together. What our brain remembers before this training is always very different from what it remembers after this training.
Many artists who draw stylized (think of cartoons) have a fundamental basis in understanding anatomy. That's what allows them to manipulate the body into a stylized form that still looks 'right'.