Notwithstanding the provisions of section four, article fifteen of this chapter if an insurer or a hospital, medical or dental service corporation elects to use a simplified application form containing no questions concerning the applicant's health history or medical treatment history, the policy or contract applied for must cover any loss occurring after twelve months from the inception date of coverage which loss is traceable to a preexisting condition not specifically excluded from coverage by the terms of the policy, and, except as so provided, the policy or contract shall not include wording which would permit a defense based upon preexisting conditions.