In the matured space industry scenario, what primary roles will NASA assume beyond being the sole operator?

Primary customer and regulator of high-speed, low-cost transport.

The predicted evolution of the space industry suggests a successful division of labor rather than a complete victory by the private sector. As SpaceX and others establish the foundational, low-cost transportation layer for accessing space, NASA is expected to transition its role. Instead of being the sole owner and operator of transportation systems, NASA will function as the essential government customer, purchasing transportation services for its own scientific and exploration needs. Simultaneously, NASA will take on the role of regulator, providing oversight to ensure safety, security, and adherence to international standards for all high-speed commercial and government traffic utilizing this new infrastructure.