Now that it was mentioned, as much as I like her, I'm not the least bit upset that Sakuya dropped out. I mean, just look at her shottypes in DDC. One is broken, the other is useless. I do remember ZUN saying he can't think of a good way to show her ability in her shottype, even before DDC. So if it means someone more balanced gets a place in the roster, I'm all for it.
(Also,I shuddered when I saw "Youmu-like gimmick" mentioned.)