When we find a CITATION.cff file in your GitHub repository's root folder, we make a best-effort attempt at parsing Zenodo-compatible metadata from it.
For backwards-compatibility, if you have a .zenodo.json file in the repository, only the .zenodo.json's metadata will be taken into account. Of course, any existing valid CITATION.cff file will still be used to display the citation box on the GitHub repository page, but will not affect in any way the metadata we extract for your published release Zenodo record.