History
Jon attended Nick Fury's briefing in the SHIELD Helicarrier about how to deal with the zombie plague. It can be assumed that he sent down to the surface along with others to rescue survivors and failed, thus he was zombified.[1]
He was part of the zombie horde that attacked the ultimate Reed Richards.[2] Though his ultimate fate is unknown, it can be presumed that he was fried when the Power Cosmic Zombies tested out their new powers.