The Packer clan have a rich history of selling assets at the top (Channel Nine and Kerry, Cons Press and James) whilst buying at the bottom....
My guess is that the independent directors would struggle to justify selling MPEL at a discount to current market, even though the holding within CWN is trading at a 30% discount. Likewise, Macau is valued through MPEL, (that value is pretty transparent), and the independent directors of MPEL would struggle with the same issue, so he really needs to buy the whole lot if he's to capture that discount value, and the hybrids are telling us that will happen. As you said, he can always re list these assets down the line.