This improves consistency when writing LaTeX content.
It also allows for a brighter future where the automatic checker can flag all mentions of \tcode{some_keyword} in the core language sections.

Does this also mean that \cname is no longer necessary?

We could apply the approach to \libconcept, too, and thus replace \cname with \libconcept in section headings, yes.

This adds a few new index entries for goto, it seems.

Ah yes, of course: the change does add new indexing, just not in the TOC.