From Nookipedia, the Animal Crossing wiki

Ellie in Welcome Amiibo:Animal Crossing New Leaf In List of villagers, I saw that Ellie will return in We [[Welcome Amiibo:ACNL...Proof? We don't have proof. I think that only animals from Doubutsu no Mori e+ (like Hopkins , Ike, Vivian) will come back. - unsigned comment from SquirrelKawaii (talkcontribs)

amiibo cards of Ellie and Boyd were also shown. here is an image that shows all of the returning villagers so far - Qyzxf (talk) 11:42, September 6, 2016 (EDT)