What If My mobile No. Is assigned to Other person??

I was wondering what happens when a Phone no. Is get disconnected. They assign it to some other person. Now my question is that,will that person able to use that no. In same way I do. Like will he be able to login in Spotify and get access to my playlists, songs etc or he will have a new account but from the same number?? I mean will he able to use all those services where I used that number,with my credentials or my all linked data will be cleared by company before assigning it to new customer! Do anyone know about it??