I know he needs to be exposed to some marketing while I'm watching along to talk about it so he isn't completely defenseless against it later, but I don't think that time is quite yet. So far, I'm going with his being able to separate "real" from "pretend" as a minimum.
Show them how it is done. How one can cut, edit and change the sound.
Ask who did it, for what reason, for which audience, to what end?
Equip them with the tools to question the things they see. Then they have the means to engage with marketing.
It’s a long road. There will be glitter and cheap plastic toys along the way.