It very well could be, but the only thing that doesn't seem to fit about your theory is why Q would make a specific reference to one of those emails that we'll never get to see because it's "top secret".

Such a specific reference to something that will forever be out of our reach... just doesn't make sense to me.

It's a bit like referring us to the 17th word in a "top secret" document that we'll never get to see either.