This article investigates the role of Wikipedia as a mechanism for digital inclusion and sustainable language preservation among two minority language communities, Setswana speakers in South Africa and the Hà Nhì ethnic minority in Vietnam. A quanti-qualitative mixed-methods design combined semi-structured interviews with Wikipedia editors, language activists, digital literacy educators, and community practitioners with quantitative Wikipedia platform metrics, including article counts, active editor figures, and content growth trajectories, was employed to investigate this issue. The results show that both communities demonstrate emergent but constrained digital participation. Their barriers are structurally distinct but epistemically convergent, i.e., infrastructural inequity, editorial gatekeeping, procedural governance, and the systemic undervaluation of non-hegemonic knowledge all recur across cases. Cross-case comparison shows that Wikipedia’s ostensibly neutral platform architecture reproduces existing knowledge hierarchies by privileging well-resourced language communities. The study introduces “platform-induced hermeneutical injustice” as a fifth dimension of digital exclusion, supplementing existing models of digital inclusion. It grounds Fricker’s epistemic injustice framework in digital platform governance and offers evidence-based implications for the Wikimedia Foundation, national governments, educators, and language preservation practitioners across the Global South.