Will it be mentioned?
Yes.
Site B Is going to need to be mentioned so they can set the stage for the next 2 Movies (Which have been promised). It's a needed element which should but might not be explained in JW.
Something I just noticed Is, Site A was cleaned up completely in 3 or 4 years after the accident... Site B was never touched after it was evacuated. Or at least not since it fell into government control after JP3 (2001), I think.
Site B is kinda fuzzy, With the main reason it wasn't cleaned up, Being John wanting it to be a Dinosaur Sanctuary, As he stated in TLW, He wanted humans to avoid interfering with the Island, And let life find a way on it's own.
Life cannot be contained, it breaks walls, crashes through barriers sometimes painfully, but uh... Life uh, finds a way
