Not entirely sure what you mean by, "they have that information." Regardless, both agents must convey all formal responses, and any material information relevant to an offer to purchase, or existing sale agreement. As I am not an attorney, this is not legal adviseâ€”but rather my professional understanding of Realtor's Code of Conduct.
They are ethically required, definitely, according to the Realtor's Code of Conduct. I think if an extension was sent buy the buyer's agent and the buyer's agent had not heard anything or gotten it back signed by the time the deal expired the buyer's agent should call the seller's agent to find out what is going on.