Shredded cheese usually does use some form of starch, however. E.g. Great Value Shredded Cheese uses potato and tapioca starch: https://www.walmart.com/ip/Great-Value-Shredded-Mild-Cheddar...

It's plenty true that cornstarch and/or cellulose make packaged shredded cheese melt weird.

Or is your argument that metal oxide nanoparticles are the only anti-caking agents that are used?