You will not get any indication from the smartthings app that the general exclusion worked, because the general exclusion can work even for devices that have never been connected to that particular controller (in this case, the ST hub). The controller doesn’t have a device ID for the device in those cases and has no way of knowing that the exclusion happened.
The general exclusion is essentially just a command which is broadcast to any zwave device that can hear it, And says “if you are currently in exclusion mode, go ahead and clear all stored information” thus returning the device To its original factory specs.
This is why you have to be careful when you do issue a general exclusion: if somebody happens to hit the particular tap pattern on a device that would put it into exclusion mode, it will go ahead and take itself off the network. Even if it belongs to your next-door neighbor. This is the main reason that the process to put an individual device into exclusion mode is usually a little weird and definitely requires physically manipulating that device.
The whole purpose of a general exclusion is so that you can reset a zwave device whose original controller is no longer available. You can’t add it to your current controller because it still thinks it belongs to the old. But you don’t have the old one. So the zwave folks came up with the general exclusion idea where any zwave controller can issue the command, even one the end device has never been joined to.
But because they’ve never been joined and it’s a full reset, there’s no response notification.
The end device may give some kind of indication like a blink pattern.
A “remove” is different from a general Exclusion because a remove is directed at a specific device that was in fact previously joined to this controller. So you will probably get an acknowledgement from the controller when that completes.