Socially Assistive Robots navigate highly sensible environments, which place high demands on safety and communication with users. The reasoning behind an SAR's actions must be transparent at any time to earn users' trust and acceptance. Although different communication modalities have been extensively studied, there is a lack of long-term studies investigating changes in users' communication needs over time. Considering two decades of research in Human-Robot Communication, we formulate the need to design dynamic robot personalities to unveil the full potential of SARs.