Yes, but WPML doesn’t support translating these strings as it is
You are correct, WPML (nor Loco Translate) doesn’t support translating strings that are created using the JavaScript wp.i81n
functions. However, the plugin is using a core WordPress API for making JavaScript strings translate-able.
Currently the advice Yui gave is the correct advice for translating strings for the plugin. When the translation percentage for a locale reaches 95% it then becomes available as a language pack for download by any WordPress site configured with that locale as it’s language. So it’s definitely advantageous for folks to contribute to having the strings translated via this way.