You don't have a choice but to seed the torrent when you upgrade; that's how it works. Using torrents outsources the bandwidth load to the customers, saves them money. What's your beef with that? It's legal.
said by 88615298
Sorry your son doesn't need to "seed" anything. Very few "legit" uses of torrents. yes there are SOME so don't go saying I said all torrents are illegal.
WoW can use some other way of delivering it's content.