Please understand that both the actions are distinct and can be applied on the Product mapping or listing defined in the system.
Product mapping creates a linking between the channel product ID and the SKU code as defined in the Unicommerce system.
By “Ignore” the system will ignore or blocked to sync the existing product mapping or listing and any order coming for an IGNORED product will go in failed orders (because of simple reason that for the system this mapping or linking does not exist)
Disable Listing: By “Disable” the system will only disable the product mapping or listing. These products are still recognized by the system and will allow the creation of orders containing disabled products. However, Unicommerce won’t be able to update it’s an inventory on the respective sales channels (because of simple reason that for the system this mapping or linking is available but disabled).