RESTAPI @controlpanel/language doesn't update language folders

[me-kell]

RESTAPI @controlpanel/language doesn't call plone.app.multilingual.browser.setup.SetupMultilingualSite.setupSite when updating data.
When available languages are changed via RESTAPI the language folders remain unchanged. Old folders are not removed. No new folders created.
According to the documentation this method "needs to be executed every time a new language is added to the Available Languages":

    def setupSite(self, context, forceOneLanguage=False):
        """This method is called from the control panel to setup a site in
        order to have root language folders and a redirect view. It needs to be
        executed every time a new language is added to the Available Languages.
        """