In "There Is No Word for Goodbye," what is the meaning of "Sokoya" in Alaskan Athabaskan?

In the Tall Mountain's poem There is No Word for Goodbye, the word Sokoya translates to Aunt which your mother's sister. The author in this poem is then showing a young woman who is afraid of losing her aunt. She asks what the word 'good-bye' is in their native language. She is told, however, by her aunt that they do not believe in good-byes instead, they say Tlaa which means see you.