Maybe the purpose of the game is to give William a chance at redemption. Bring Juliett back.

The game starts "at the beginning". What made MIB come back? Death of his wife. More precisely his daughter telling him it was suicide due to his "darkness" which I take it to mean general MIB douchebaggery. I can imagine comments like "those bots are more real than you could ever be, honey".

Intro of Emily is giving off some support, perhaps shes after the tech to rezz her Mom. But what if Ford foresaw all this? Maybe the final piece is a human heart or something that requires MIB to give a soul for a soul.

So the extra module berdard printed is for Juliett.

Whose picture started all this? Juliett.

Whose death got MIB back? Juliett.

Who would be the only kind of people that deserved to be brought back? Those that really dont want to, but might appreciate life better after ending it willingly.