I don't know why you'd think that can work in the first place. If you delete the entire project, it is gone. There's no feasible way to then resurrect it later just because the name or URL is the same. And even if there was, there would be no way to know if the new project was even intended to be retroactively updated to appear in the same places as before. What if someone else creates a different project down the road that just happens to have the same name, should it get added to people's library who downloaded your old thing?
Projects can have the same name. And the same title. Usernames can not. And project urls are tied to the username.
Furthermore projects have an ID. I saw some peculiarites happen, but for the most part, the ID is not only unique, but it counts up. And to identify games in collections or purchases, the ID is used. If someone deletes a project and creates it new, even with same url, it has a new ID and will not replace the old one in collections. It is for all intents and purposes a new game. It gets worse, if the old game gets deleted, it will silently dissapear from collections, leaving a hole in them. A collection page has 36 items. If you open a collection and see only 35 items on a page, one of the items was removed. Possibly due to the issue I talk about here.