Sale of the company or the end of governmental funding might constitute such an event. The team needs to carefully plan its communication with its larger community of interest. The same question applies to all customers who will experience changes wrought by the High Performance Team. The community of interest includes people who will be affected by the changes the team makes and those in a position of authority to approve or disapprove the changes. Finally, other non-involved organizational members need to be told about the work and charter of the team.
People imagine all sorts of things are going on when teams form.
Usually the imagined possibilities are quite negative. Any secret team is going to be discovered and the rumors are going to start flying. Therefore, the official position of the team needs to be very open and honest about what it is doing and why it is doing it. Work in progress should be explained as just that. Honesty and openness are the only real defenses against the rumor mill.