Naruto getting sent to another dimension by Kaweki could be a good way of keeping him and Sasuke out of teh way of stealing Boruto's limelight. Sasuke could spend his time searching for Naruto thanks to his dimension hopping abilities and their lengthy absence could be justified by saying that dimension hopping, although it feels like seconds to teh user, it can take months/years to hop from one dimension to teh other. So yeah, Kaweki didn't/can't kill Godruto and his family. Sasuke's unaware of teh current events because he's in a different dimension on a business trip.
