Addons, Textures and Shaders are still present when deleted from the Storage tab

When I was about to install the latest version of a texture pack, Shader or Addon, I have to delete the old version. But, as I deleted the old version from the Storage tab, I realise that the old version of whatever I deleted (For example: The Netherking Addon) from the Storage tab, the thing that I chose to delete from my game would still be in my worlds, as whatever I deleted from my Storage tab was supposed to remove the same thing from my worlds. This has been a serious bug that has happened prior to the 1.12 update. Please fix this.