Board Thread:Questions and Answers/@comment-25345226-20140825000544/@comment-1466854-20150112033240

Yeah, not surprised by that. Generally speaking, games like this are produced with the intention of making money with as little effort exerted as possible. The Vita version, compared to all other platforms, is extremely low-traffic and updating it is unlikely to encourage new purchases beyond what's already been made. As such, it's not of interest to them to keep updating it.