Disabling system apps on Android doesn't just hide the icon, it stops the app from running (e.g., via intents or other means by which you can run an app without clicking on the icon.) It's in practical effect no different than deleting a non-system app, except that physically the app is still in immutable storage on the device and can be reenabled without being downloaded (barring any subsequent updates to the bundled system version, which would need to be downloaded.)