It’s recommended to backup your WordPress and WooCommerce website before enabling this option. But you don’t have to the backup. When you create a new product in WooPOS, you still need to go to “Web Info” and “Publish” the product. If you changed a web item information like price, description(title) in WooPOS, and you have the “Automatically upload online products when changes made in POS” option switched on, the item info will be uploaded to WooCommerce site automatically. Attributes will be uploaded, but departments won’t. For details, please check here:

WooCommerce Data Synchronization