
Language documentation, vitality assessment, maintenance, revitalization, and reclamation address related dimensions of threatened-language futures. Their objects remain distinguishable: documentary resources may endure while learning pathways contract; programmes may attract participants while material barriers restrict sustained participation; standards may aid teaching while distributing linguistic authority unevenly. This position paper develops a philosophical and formal synthesis centred on successor formation and community-governed language futures. The literature discussion reconstructs antecedent work on documentation, intergenerational transmission, socialization, situated practice, new speakers, political economy, language rights, capabilities, and Indigenous governance. Within that synthesis, generative linguistic continuity receives the limited status of a proposed diagnostic term for the capability to form successors, sustain situated practices, create and receive expressions, and govern future trajectories. The formal core separates documentary capacity, effective opportunity, realized participation, direct and regenerative successors, viable trajectories, barrier interactions, and reference constraints. Conditional results establish documentation–generativity underdetermination, an opportunity ceiling, partial profile comparability, and trajectory contraction under nested fixed-reference rules. Constructed cases, objections, and evidence gates delimit empirical use. The resulting framework remains revisable and requires longitudinal evidence, community-specified objects, and explicit normative premises.