This is a smart idea to have actual liquidity of a token long before an ICO ends. I think this is a very good idea and if implemented successfully it might set a precedent of things to come. I have seen so many ICOS go bad because of no liquidity for the tokens they issue and also some tokens do not even get listed ever on an exchange and are rendered already useless. Now also it is harder and harder for new projects to get listed on exchanges so this might help in easing the tension of investors into new and upcoming projects.