Copyright holder can do anything he wants with his code, so yes, John can rerererererelease his own code under different license. However, you cannot do that, e

Copyright holder can do anything he wants with his code, so yes, John can rerererererelease his own code under different license. However, you cannot do that, even if the copyright holder told you something. He may change his mind tomorrow, or in a year, so you will have no legal ground for this act of piracy then.