Unfortunately, once the app is deleted from your device, all your artworks are lost and become unrestorable.
Even if you are able to see the artwork in Get Inspired and Most Loved with your name or Guest Number, it is not possible to connect the artworks to your new account.

Keep in mind that deleting or reinstalling the app will erase all your images. You can save your Published images and your account's social data, such as Loves and Followers, by linking your account to Facebook before deleting the app.