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.
Exactly that's what we are looking forward to, ICO's in its current form might die soon and bring bad reputation to the whole ICO business, transparency, liquidity and non vesting will be good for both sides, investors and teams although it will be more about intuition-driven decisions from investors side but still it will make a big difference.
At least here in Dappvestment, we offer our investors the choice, to vest or reserve and in both cases they earn the bonus but people who reserve earn way less bonus. Following such model, the need for listing on exchanges won't be an urge.