In "Everyday Use," what do Dee's new name and costume and her concern for her heritage have in common regarding social movements?

Yes, Dee's clothes, name, and concern for her heritage reflect the Black Pride movement of the sixties.  Dee wants to celebrate her African roots, a desire that  Alex Haley's Roots inspired in Americans throughout the decade.  And yet, Dee's new interests are portrayed as whims and fads, and somewhat materialistic.  She is not really interested in the butter churn as a butter churn but as a center piece for the table.  She wants the churn for display, not for use.   She suddenly wants the quilts because she knows that they are handmade and therefore valuable.  She is not interested at all in the woman who made the quilts.  She has no true interest in her own family or relatives, but only in a created past.  She takes on an African name because she does not want the name of a slave owner, yet she was named after her grandmother. 

Through Dee, Walker seems to be satirizing the sudden interest in African heritage while neglecting  and not appreciatiing the history of one's own family and relatives.   It is Maggie who remembers her Grandma Dee, who knows her true roots, and who knows the true value of the churn and the quilts--not their monetary or aesthetic value but as representative of her family members who made and used them.  It is Maggie who therefore rightfully deserves the quilts.