I’m inclined to say no. Not because of fungicides – suppose all tree species carry those to defend against fungal infections – but more because of the fairly big pores in black walnut. They would probably readily absorb liquid food components, which would be attractive growth-media for potentially infectious bacteria.
Ring-porous woods, like oak (please see attached photo), evidently exit a lot of interesting chemicals into liquids, as anyone who overindulged on a decent Bourgogne (attached photo portrays a recommended one) can testify to.
Circumpolar native populations have traditionally depended on Alaskan Paper Birch (Betula Neoalaskana) and Scandinavian Mountain Birch (Betula pubescens ssp. czerepanovii) for bowls, spoons, and ladles. Perhaps, over the several millenia of use, it was learnt that these woods, with their nearly non-existent pores, were less associated with infections than Scots Pine or larch.
Dense North American Beech (Fagus grandifolia) is another wood resistant to the penetration of biologic fluids. It would be very unlike a gentleman to reveal how I know this: more I would refer to the extensive use of beech for cutting boards.