What conspiracy?
I see this all as the normal machinations of a company trying to keep it's customers pacified. They set a value on Bay and would not budge. Probably for good reasons (knees, shoulder).
The Sox made a solid offer last summer which was rejected. They made another (lesser offer) just before signing Lackey. It did not work out. Now they are forced to promote a "Run Prevention" roster and philosophy which may not work out. If that happens, fans will be screaming "They should have signed Bay 'cause they can't score runs". "Leaking" this story is most likely an effort to cover their asses in the event the offense is inadequate. It's just spin control, that's all.
I think it's very unlikely that the actual source of this story will ever be known. But I see no reason not to believe that someone in the Sox organization said something to someone after Bay was gone.