Not a joke ;D
https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.ato.ru%2Fcontent%2Fyak-40-prevratyat-v-dvuhdvigatelnyy-samolet&edit-text=
http://www.airliners.net/aviation-forums/general_aviation/read.main/6282641/
What will they do with the space the third engine occupied? Leave the passage hollow and turn it into a flute? A flying Oboe, complying with Chapter Beethoven standards?
Yes, it will be empty to not have to redesign the tail (costs money). This is intended to be a cheap and easy mod.
Making it into a flute may make it a very unique aircraft ;D