No way. This kid wasn't brought in for info. If so why wait so late in the week?!
There are advantages and disadvantages to a late intelligence signing vs. an early one. Overall I think the late one has more advantages.
Early - You can pump for more info and game plan with that info.
Late - You don't have time to add new plays based on what you learned. But the opposing team doesn't have time to make adjustments either. You learn of any game/team specific planning and plays. Even if the player doesn't sing the opposing team has to assume he is that means that they can't use the "surprise plays" they spent the week practicing. The Dolphins know the base Jets offense and defense. What Brown can tell them is what adjustments and changes were made between the Ravens and Patriots game.
I am not saying the Fins won't keep him, just that the lateness doesn't mean it isn't intelligence gathering.