With this research we investigate how to account for multigenerational perspectives in the design of multi-lifespan information systems, particularly in support of long-term peace-building and international justice. We do our work in the context of the publicly available Voices from the Rwanda Tribunal testbed, a historically significant collection of video interviews with personnel from the International Criminal Tribunal for Rwanda. In the research reported here, we worked with 109 Rwandan adults and youth from perpetrator and survivor communities in three provincial cities in Rwanda (Byumba, Kibuye, and Gisenyi) to understand the potentials and challenges they envision for the interview collection. Participants envisioned five categories of long-term positive outcomes for individuals and society from a multi-lifespan information system for the interview collection; and eight categories of challenges to realize those potential outcomes. In terms of multigenerational perspectives, while adults and youth tended to share an overall vision for the long-term potential of such a system, adults emphasized actionable tasks while youth educational benefits. Based on the findings, we highlight issues for appropriation of multi-lifespan information systems and reflect on our methods for eliciting multigenerational perspectives on information system design in a post-conflict society.