I'd also like to see this implemented but from what I can deduce, there are a few issues with picking an already translated novel, so often times it's much easier to start translating a new one and unless the dropped novel was really popular, which it probably won't be due to it being dropped, the newer novels will win out. The main issue is that due to the missing translator, the ratings of that story have plummeted and the lower star rating you have, the less popular the novel is going to be. There's also the issue of conflicting terms, the previous translator might have translated one thing, but the other wants to change it, so the mid-story change can be quite jarring and if the novel already has 400 chapters translated, there's no real option of going back and re-translating the whole thing again. I'd also imagine that a better translator might not want to continue a story which contains lower quality translated chapters, but what do I know. I'm pretty sure there are more problems with this than what I can list off the top of my head. I don't have any clever solutions, but I hope that the community can come up with some.