(i) Millions of kids saw that episode and went on to pirate movies and music anyways, because kids don't really derive their ethics from cartoon series, just like you & I aren't secretly animated by "Knowing is Half The Battle" from G.I. Joe. (http://www.joeheadquarters.com/joeendings.shtml)
(ii) The particular message you're suggesting Iron Man is "propagandizing" is so anodyne that it was the subject of a whole episode of Arthur on PBS.
When I was a little kid, Saved by the Bell was a really funny show. I loved watching it. I read books that had the same characters as well. In one of the books, one of the girls was saying she couldn't date a certain guy. Her friend asked her why not. She said it was because they were already friends, so it would be too strange to date.
For years after that, I thought it was a stupid idea to date friends. I thought I should only try to date strangers or acquaintances, which was hard because I was timid about that kind of stuff. My parents didn't even get involved because they didn't think it was important, and that I'd figure it out. So my dating record during high school was zero, and even during university, it wasn't going anywhere until very late in the game. During this time, I passed up on the opportunity to date many wonderful girls who were high in character, very attractive, etc, just because we were already friends. No, I had to find someone to date who was not yet a friend, except I couldn't get date-comfortable with girls without becoming friends first. What a stupid infinite loop.
It's a stupid and embarrassing story, but it did indeed happen. And as dumb as it is, I've only in the last few years overcome that completely illogical obstruction in my mind. Parents, talk to your kids about what they watch on TV, play on their PS3, and read in books. Ethics may or may not be impacted, but if behaviour can be impacted, I bet you ethics could be as well.
The point of such propaganda would not be to ensure that people don't pirate, but to plant the idea that doing so is morally bad, so that lobbying efforts in favor of IP protection laws seem morally legitimate.
Is it really that tin foil hat-ish to suggest that Disney has a boat in this race, and might try to exert some influence through their content? Hey, maybe they aren't, but I definitely don't think it's terribly far-fetched to question it.