Hi keturn! Exploring how reviews and repositories should interact is a question we constantly struggle with. It turns out to be a high-dimensional problem space concerning our current website design and our code's architecture and how Kiln interacts with FogBugz. Currently we don't have any plans to allow users to change which repository a belongs to; recreating the review is the best I can offer.
However, I can't help but think the existing review UI already makes it very clear which repository a review is tied to: