Json is a language?

Yes. A small (but extremely popular and useful) domain specific language for describing arrays and objects and scalars.

Sanity checking with wikipedia to see if I missed something, I'm going to have to disagree.

Json is a data exchange format and while ubiquitous and well defined, it supports none of the elements that make a computer language a language.

We classify JSON as a "dataNotation" (line 4 on https://github.com/breck7/pldb/blob/main/concepts/json.scrol...)

We classify something like C as a "pl" (programming language) (line 4 on https://github.com/breck7/pldb/blob/main/concepts/c.scroll).

We classify both data notations and programming languages as computer languages (https://github.com/breck7/pldb/blob/4b7f689244a0f5dc0d99fb31...)

I do understand where you are coming from though. Someone could certainly do a post on whether there are any programming languages that don't have comments. At the moment, 100% of programming languages that we have that data for (>600) have comments. https://pldb.io/lists/features.html

I think this makes JSON interesting, especially given its backstory of once having comments.

It's not a programming language with semantics, but it is a https://en.wikipedia.org/wiki/Context-free_language in the sense that we have a grammar specifying which strings are valid.