HI
I think that this feature will be really useful because when we deprecate one app, we don't want to erase the script key, in order to maintain a historic of all our developments, so a way to only make that key useless to access shotgun will facilitate the way we grant access to the site, and avoid users to use deprecated apps.
Also, another useful feature, will be a way to regenerate the api key, instead of remove the entity and create a new one with the same name, only a right button "recreate key" option and vuala, we have a new api key for this script.