What is your idea?

Add the c:foods item tag to edible items - 1.21.1 Neoforge.

Yes, can do that. Is there anything special that will benefit from it.

Sitenote mostly to myself:
Since Forge now also moved their tags to the c namespace, I will be reworking the tags for all 1.21.2+ versions
The item tags could need a rework accross all currently released mod-versions.