From the
Model Mayhem FAQ:
What happens when I unsubscribe, downgrade, or cancel?
When your account downgrades, you will lose all your subscribed features. You will go back to only having access to the basic features outlined here: www.modelmayhem.com/upgrade
Please note that your images will not be removed if your subscription reverts back to basic, they will either be hidden if in private albums or reduced to the amount allowed in basic profiles.