Dear Yes, Virginia, There Is A Spy In Our Midst,
Huh. Well who'da thunk it? Granite Flats is apparently getting a sequel series.
It's hard to say if this new series will answer the poor reader's questions, though, because the series hasn't aired yet. From what I can gather, it looks like the pilot has been ordered, and maybe even produced, but if it has been made I don't think it's been aired yet. Unfortunately, that puts it in fairly shaky territory: not all pilots make it to air. Still, if it does come to fruition, I'd say it definitely seems like it might tie up whatever plot points were left hanging (especially because, as I gather, there's a character named Arthur whose father might have vanished in Moscow, and this new series has to do with spying and the K.G.B).
Fingers crossed that Web of Spies makes it to air, I guess!