They are undoubtedly referring to the highly controversial Nostratic language family hypothesis, which postulates a language superfamily that includes most of t

They are undoubtedly referring to the highly controversial Nostratic language family hypothesis, which postulates a language superfamily that includes most of the large language families of Eurasia (i.e. Indo European, Semitic, Dravidian, Uralic) and also the proposed "Altaic" family which (also controversially) is comprised Korean, Japanese, and Turkic. Nostratic excludes the Sino-Tibetan family (i.e. Chinese languages), most languages of Southeast Asia, and all the African languages. https://en.wikipedia.org/wiki/Nostratic_languages https://en.wikipedia.org/wiki/Nostratic_languages Again, it's so broad a grouping, projected so far back in time and based on such weakly detected feature similarities, that it's by no means broadly accepted as a language family in the way that Indo-European, Semitic, Uralic, etc are.