The USACOE provides funding for the Lower Snake Mitigation. This funds at least the Lyons Ferry Hatchery operation. Since it is mitigation for the dams, lack of dams removes the legal reason why they fund them. Money can still be provided, hatchery fish can still be produced, but I doubt it can come for mitigations for dams that don't exist.

As soon as the dams are removed the impact begins to go away. Then, the reason for lack of spawners amongst the wild stock becomes the direct responsibility of the managers; they can't blame the dams.

IF the hatchery production is discontinued, then the wild smolts will undergo increased predation in the mainstem Columbia as there will be fewer salmonid smolts of the remaining predators to chow down on.