The problem with your analogy is that the game isn't replicating the events of 1984. It's more like if someone, 5 years from now, made a game where you attack gun-wielding businessmen in a large building suspiciously reminiscent of the World Trade Center. I'm sure some people would be offended just by the presence of the WTC in a violent game, but these are the same people who get bent out of shape from just about anything.
It's not like the game is making a specific reference to the 1984 happenings. In fact, I could almost guarantee that the temple in hitman is only superficially similar to the temple referred to by the Sikhs. And really, its inclusion in the game is more of a tribute to its fantastic architecture than anything else. It's a bit unfortunate they fell to the standard stereotype of turbaned Sikhs as thugs, but I suppose there's a ready analog in the devout Catholicism of mobsters as portrayed in the Godfather or countless other mob movies.
This is just one more example of hypersensitivity spiralling out of control. I thought it was a problem endemic just to spoiled Americans, but apparently it's a global plague.