This early, they’re probably running costumer/data experiments on out of stock scenarios. How long can a thing be out of stock before its sales dip upon return

This early, they’re probably running costumer/data experiments on out of stock scenarios. How long can a thing be out of stock before its sales dip upon return? Do users who regularly buy those things stop visiting? Buy other products in the same category? (Do they switch back when stock resumes?). Etc...