To remove or "de-list" a title (or a previous version of that title) on a distribution site is a difficult task to accomplish. Distributors purchase and retain copies of a title, and will continue to show availability as long as they carry inventory for that title. In the case of a distributor such as Amazon.com that allows sellers to set up virtual "stores" on their site, this is nearly impossible. These sellers may have new or used copies of the book and these copies will also show availability through any numbers of "Sellers."
Once a title is depleted, at least at the distributor level, this title should then either be shown as "title unavailable" or if there is a new version, this new version should generate the first "hit" in the title search within that site. However, any used copies for the original version of that title may continue to show as available for purchase.