From our Press Sneak Friend
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This was actually cut from my article late last year - yes, 343 spent a while prototyping a hero-based system. I don't remember exactly when they switched to the current version (and the tweet linked here seems exaggerated to the point where it's mostly false) but I can confirm that they were working on various hero-based prototypes. In fact, I think there were both PVP and PVE prototypes built.
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