Legal Question in Intellectual Property in New York

This is not an intellectual property question. Intellectual property deals with property of the mind: patents, trademarks, copyrights, trade dress, licenses, franchises, that sort of stuff.

That said, your bank accounts are presumably not your only assets. You need a Will to distribute ALL of your personal property as you want it distributed, not as it would be distributed under the laws of intestate succession (distribution in the absence of a Will).