When a new Review is created, you warn me if the assigned Reviewer does not have Reviewer access, and you give them the required access if I choose to continue.  This is the appropriate time and situation for the warning to appear.  When a new Review is created, you also warn me if a previous Reviewer on a completed Review does not have Reviewer access.  This is an unnecessary warning at this time and in this situation, I am not trying to assign a Review to this individual.  You will eventually warn me again at the appropriate time if I ever try to assign a Review to that individual in the future.  Warning me that a previous Reviewer no longer has access is totally unnecessary.