This is a huge victory over the PJM cartel, who has attempted to limit the building of new generation on the east coast in order to preserve the transmission and capacity revenues of their favored incumbent generators of dirty, coal-fired electricity in the Ohio Valley, the "PJM Power Providers Group."
A similar power struggle over new generation is occurring in New Jersey. The two states are currently faced with some of the highest electricity costs in PJM. PJM, on behalf of the "power providers," has been fighting the states at FERC, insisting that their markets are working to stimulate new generation. PJM's farce is no longer working.
So, with both New Jersey and Maryland building new, cheaper, generation, there's absolutely no "need" for PATH or other Project Mountaineer transmission lines (not that there ever was). Just one more nail in the moldering corpse of PATH's coffin.