Board Thread:General Discussion/@comment-28866382-20161009202006/@comment-26871105-20161010020519

Togashi is not Oda (author if One Piece), who is known to connect most of his characters together and mention earlier or even re-introduce them in later arcs. Togashi is like Araki (writer of JoJo's Bizarre Adventure) when it comes to writing, most of the characters besides the ones playing much bigger role in the overall story are arc-specific and rarely do they appear across arcs.

So it's very unlikely that we'll see the prisoners in Trick Tower ever again.