1.) the coin isn't lauched, it might happen the same
2.) to let iou exchanges out of the game, isn't fair for investors. maybe they are stupid, buying waves for 2million sat. but it is buyers risk.
at the moment waves lost most of its credibility to me, if this is true...
exchanges can trade whatever they want. yobit and bloombit are trading their own IOUs. No one can stop them from that.
You cant deposit or withdraw the waves anyway to this exchanges. As mentioned by others, its not sure if you can withdraw or deposit waves even after the launch, so you will have to keep it there for longer what is not a bad either.