There is "fresh" and there is "fresh". That said, I have had plenty of hybrid, and a few species, Hellebore seed from society seed distributions and Archibald, that has germinated freely, which will have been dry-stored for several months.
Presumably you are implying that some commercial suppliers keep stock for more than one year? I have never sown Hellebore seed that has been dry-stored for longer than several months so can't comment on longevity.