Given that the RAF has effectively given up on retaining any anti-shipping capability, can you think of any better place to attempt to retain those maritime skills, and teach new Navy pilots how to attack ships? By the time the F-35 comes into service those skills will have been lost to both services.
Imagine it as a kind of seedcorn project, keeping the maritime strike skills alive.
My guess is the Navy will get more hand-me-down Hawks based at Yeovilton as part of an expanded standards flight. It may not be perfect, but desperation measures are required.