Google's Gary Illyes said that hreflang alternates, hreflang URLs are not "indexed in the proper sense." In short, Google just keeps the hreflang URL as alternate URLs. So the URL is not what is getting the page indexed, it is just being stores as an alternative to the main page URL. 2. hreflang alternates become such alternate URLs: they're not in fact indexed in the proper sense. While the specific URL might not be indexed, the URL is mapped to the canonical page that is indexed.