At the end of the movie, Homura and Shizuku are giving their goodbyes to Rukia before appearing to pass away. But what happened to them? They are half soul, half hollow, so did they reincarnate to The World of the Living due to their soul half or was their existence completely wiped away?
As explained by Rukia using her Chappy drawings, hollow are souls who have been corrupted by sorrow.
Shinigami's job is to purify these negative souls so that they becomes plus. A plus soul can enter Soul Society and wait for their turn for reincarnation.
Thus, to answer your question, Homura and Shizuku was purified (forget whether it was Ichigo or Rukia). Thus, they would become plus and wait for their turn for reincarnation.