Upon the entry of a decree of divorce, either a mensa et thoro or a vinculo matrimonii, all rights of either consort in any multiple-party account then existing between them, including the right of survivorship, shall be extinguished; and any joint account then existing between the consorts shall thereupon be converted into a tenancy in common, in the proportions provided in subsection A of § 6.2-606, unless otherwise ordered by the court.