From what I hear, the Mima yukkuri is something made up by a crappy western artist, and isn't recognized by anyone else. I imagine the same is true for all the other PC-98 yukkuris. Just as well, because Mima's the worst character ever. :p
For reasons that have very little reason to do with her I'm sure. There are many characters from PC-98 more endearing than Ms. doesn't know if she's evil or just annoying weak final boss that everyone curses ZUN for never bringing back even though Yukari usurped her role of annoying Reimu and a reappearance would make no sense.