So if this is not a fetch quest, then what is?
Note I am not complaining. I've always argued that most RPG quests can be reduced to fetch quests when you get down to it. That's why it's ridiculous to complain that an RPG has "too many fetch quests"/
And it seems the developers of the Witcher jumped on that bandwagon and bragged that their game would have "almost no fetch quests", and here we see a game play demo and bang, a fetch quest.
Like a lot of videogame jargon, "fetch quest" seems to be one of those where some people use it in its most literal sense while others use it figuratively. I fall into the latter just because the literal meaning of "fetch quest" is far too broad to actual mean anything -- like you said, just about everything in an RPG can be drilled down to a "fetch quest". Its like saying I hate "conflict movies".
When most people talk about fetch quests, they mean quests with barely any purpose or emotional involvement. It feels menial and meaningless, but you do it anyway because you want the reward. Its exactly like a dog fetching his master's newspaper. The dog don't care about the newspaper or its purpose, hes just doing it to get a treat.
If this quest was just the guy asking you to get the box and then you return, get some exp, and never see him again... it would definitely be a fetch quest. However, its multi-layered. There's actually a story with some twists and turns, the outcome is left up to you, and it seems like it ties into a larger story. In contrast, there's quest in Inquisition where someone asks you to deal with rogue Mages throughout the lands. They marks 5 locations on your map, you have no idea who these Mages are or their motivations, player engagement is just go to the X and kill them. When its all over the NPC just says "thank you" and they like you a little more. Unfortunately, that is how a lot of the side quests are handled in that game.