Proposing removal of subscription record upon unsubscribe

Currently both subscribe and unsubscribe operations to a feed execute the same code resulting into the same behavior.  As a result subscription records created in the database have the same state and we can't tell which ones were unsubscribed and which ones are still subscribed.

I am proposing to keep the subscribe operation as currently implemented but tweak to unsubscribe operation as the following:
1) when the unsubscribe request is sent to the hub, update the subscription record STATE column as to_delete
2) once the hub sends the callback and it's been verified, delete the subscription record

Please let me know if this fit the original design ideas.