Products deleted in SynCommerce are either deleted only from your SynCommerce account, or from your store as well.
Merchants have the power to indicate what the system should do when deleting products. By default, products deleted are deleted on SynCommerce, and remain on the store. Merchants can however tick a checkbox for the system to delete the products in question on the store as well.
For any further questions, contact SynCommerce on firstname.lastname@example.org