"...NP, it should be OK to let us know if they are still continue without violating any non-disclosure agreement."
No, because in most cases the other party does not update the property owner as to whether or not their interest level is increasing or decreasing.
My advise? Forget about it. As I said earlier, almost all none disclosure agreements go on forever without any proposals being presented. Odds suggest that that will be the case with this agreement covering NPSP.
VP