I see that messages for a rest API are being added to the core i18n/en.json file.
They look very technical and probably useful only to developers of tools and gadgets, similarly to Apihelp. If it's certain that there will be fewer than a dozen of them, then it's OK to just leave it as it is. However, if their number is going to grow, they should be split to a separate i18n file as early as possible, as it is done with Apihelp, Installer, and Exif.
The patch itself will be trivial, but it's better to understand whether it's needed at all.