Stallman hasn't been a significant technical contributor to any GNU project for more than a decade. Making important contributions to a project doesn't mean you own it forever - it's a bittersweet fact that groups, organizations, and companies can grow and evolve in ways that are incompatible with their original founder sticking around.

The FSF owns the copyright to most GNU projects, and RMS has resigned from the FSF. It's unclear why he would continue to have any formal authority beyond his personal power of persuasion.