When a package is deprecated it is no longer available by searching the Asset StoreA growing library of free and commercial assets created by Unity and members of the community. Offers a wide variety of assets, from textures, models and animations to whole project examples, tutorials and Editor extensions. More info
See in Glossary. As far as new customers are concerned, it is removed from the store. However, customers that have already purchased or downloaded the package can still download the package.
Once you deprecate a package, you need to submit a new draft for review.
To deprecate an Asset:
Open the Asset Store Publisher portal and navigate to the Packages tab.
Select the Published view in the drop-down menu.
Click the name of the package you want to deprecate.
Scroll down to the bottom of the page and click the I agree to have the package deprecated checkbox.
Click the Deprecate Package button.