Do you show prontography to your 5 year old child ? I doubt it.
Murderous blood and realistic violence: yeah, sure, he can handle that. But I bet you draw the line about showing him prontography.
And "context to understand it when he is exposed to it." I don't know, perhaps he'll run into a lot of Flamethrowers and futuristic annihilation weapons in CANADA, but I doubt it. Because, it's Canada. And because the whole "UNREAL" thing.