I am not an owner of any of the vacation clubs.

This seems like a positive change based on publicly available information. All three programs are rolled into one which benefits members. The name Abound by Marriott Vacations is also good. It is associated with Marriott but not directly Marriott. Marriott Vacations (VAC) is not part of Marriott International (MAR). The two companies have a marketing agreement but are otherwise separate companies.