There are several types of soft opennings. Some private, some public. when there is a new ride/attraction, the first to receive soft opennings are the cast members, then there is a soft openning for AP holders and DVC members. After those groups get their well deserved special treatment, there are soft opennings for the public. What it means is that at any given time the attraction MAY open to the public and if it does, you are more than welcome to attend. However, you most likely will not know it's going on unless you are at the park when it happens. During MS, the CMs would put a sign out letting folks know that it is curently operating.