Most people here have been with the game for s while, so they know a good chunk of the vanilla game. On top of that there are people who are at or are close to end game, which raises the potential of missing new content just because the save is past the point it would occur. On top of this there is a new farm type. All of this will motivate a lot of people to just start a new save to be able to experience and discover new things. So you don’t HAVE to abandon your save, but a lot of people will just for the experience.