If a life insurance policy is less than 2 years old and the holder dies, is it legal for the company to deny the claim if the 2 year rule isn't stated in the paperwork?

I am so sorry for your loss.  More information is needed here.  Why is the life insurance company disclaiming coverage?  Was there suicide or fraud or misrepresentation?  There should indeed be a clause that states any right to disclaim or void the policy but it might not be specific (i.e., 2 year rule) since state law can change.  If you think something is wrong file a complaint with your state Insurance Department and have an attorney review the documents.  Good luck.