To answer your question was the exhibition done after his "death"? Yes, it was. It clearly states on the website: "Michael Jackson: The Official Exhibition is open for only three months at The O2 bubble". ;)
It's odd that Miko wrote a note "telling Michael not to worry and he has a list of everything and will bring it back like you told me to." Why would Michael tell Miko to bring everything back if he's dead? :? Why would Michael eve nwant the stuff back if he's dead? I would think they would put things in storage or somewhere for keepsakes.
I agree, we need to investigate Miko more. He defiantly knows something! ;)