Shockwave's Hand

In MTMTE Pt.1 we see Shockwave had 2 hands instead of his Laser Cannon as seen in this picture 
Does anyone know what happend during those 4 Million years? Were times tough on Cybertron & he had to seel it for Energon just to keep functional? Did he lose it in a game of poker with Swindle? Tell me what you seriously think happened(a little joke now and then would still be nice).

Does anyone know what happend during those 4 Million years? Were times tough on Cybertron & he had to seel it for Energon just to keep functional? Did he lose it in a game of poker with Swindle? Tell me what you seriously think happened(a little joke now and then would still be nice).