"You are Forerunner!" 343

In halo 3, near the end, 343 GS declares to Chief, “You are Forerunner!” So did Bungie intend to have humans as the forerunners? Or does 343 GS confuse Chief to be Iso didact, who activated the Halo arrays last time? I always had a doubt in this regard.

It always seemed to me like Bungie intended for humans to actually be forerunners. Obviously 343 have changed that, if that was ever the intention to begin with. I personally dont mind since I like the version of forerunners we have now, but that dialogue from 343 GS is definitely confusing. I’m sure that there’s lore out there somewhere explaining why 343 would say something like that but I’m not familiar with it to know the answer.