if you have changed your address and never updated on your super. your super can not contact you for a while, then your super company will classfy you as a lost member. your super details will be handed over to ATO. if you think you have a lost super, you can conduct a search via ATO.
no. super cannot access this data. if you think you have super elsewhere, you need to update the address by yourself. or you can conduct the search via ATO. and find your lost super, claim back or consolidate them to one super at your choice.