If you have selected the Specific Products option under the ‘General’ settings, you will get the list of the products to select for displaying the Pre-Order option.
You can select the products to display the Pre-Order option only for those products. By enabling the Pre Order Status, the Pre-Order option will appear on the product detail page.
You can search the products and navigation is also provided to check the product list.
If you have selected the All option under the ‘General’ settings, you will get a note that Pre-Order options are enabled for all the products.