The whole smurf thing has been blown out of proportion... by both JWs of that time and ex-JWs since then.
Tales of demonized smurfs and the subsequent smurfology (the repeating of gossip regarding talking and/or walking smurf dolls, dancing smurfs on bedspreads or curtains)was a grass roots movement among JWs. It wasn't a sanctioned effort by the GB or the WTS. Dubs are so superstitious and fearful of anything that might be demonized that it doesn't take much to get em all worked up. Let someone get all worked up about smurf magic on a Saturday morning cartoon and they'll tell a good smurf demon story and then have it get picked up by an elder for a talk and pretty soon it spreads like wildfire across the circuits.
It struck a chord with the really cult indoctrinated and naive. They really bought into it. Meanwhile, more rational and sensible dubs laughed at it (at least quietly and away from the nutters).
Over the years the story has stayed somewhat entertaining because it is so silly. As ex-JWs, we like to point to this silliness as one of the more tangible pieces of evidence of just how nutty the JW religion can be. You can argue doctrine and dates all day and the average person will yawn, but mention that JWs were afraid of..to the point of unofficially banning... anything smurf related and people sit up, take notice and start to chuckle.
The new smurf movie will go by unmentioned by the WTS because they don't really want to encourage the dubs to get all stupid about it again. It's not about demons, real or imagined. It's about the reputation of the organization. By encouraging the irrational behavior of condemning silly cartoon characters it only serves to give them bad press. They're probably hoping that the movie comes and goes without much fanfare. But - if the movie is a blockbuster, it will be interesting to see how many dubs, on their own, remember the old smurf scare from way back when and try to resurrect the fear and superstition all over again.