You have it exactly backwards. Starlink is attempting to block competition by moving into orbits not assigned to it but which have been targeted by competitors. Starlink had the option of using the lower orbit when it designed its system, and chose not to even consider that orbit until Kuiper was announced.

Every other company in the space is opposed to this move, because Starlink's unilateral reconfiguration would interfere with nearly every other company's operations. Part of the FCC's mandate is to prevent that from occurring, and SpaceX absolutely deserves to be slapped down for its anticompetitive behavior.