(I cannot reply your post, so I made a new post.)
The first thing that should be clarified is that the reason you got a RFE is because you asked for expediate processing. Otherwise, TSC will contact VSC and get the approval notice directly. It means that if you did not ask for expedite processing, nothing would happen.
Secondly, why you did not get your approval notice until now? It normally only takes several weeks to approval waiver. Are you sure your application is still under processing at VSC?
Since you are already here, a sure thing you can do is to call VSC to check if they've approved your waiver, then you can contact VSC to asked for a duplicate approval notice by submitting I-814(not very sure, but you can find it on DOS website). This may cost you about $200. Once you get the approval notice, you have enough time to submit your RFE. luck!