Why would shared album reappear after being deleted from device.iCloud?

If I accepted a shared album from another device onto my iphone, deleted it, but it showed up a year later, how could that happen? Share album is through iCloud

You don't delete them, you unsubscribe from them. If you unsubscribe from a shared album then it won't appear again unless they invite you again and you accept it.

If you never unsubscribe from it then it will remain on your device until you do or if the person who shared it revokes your access