I feel like we should probably establish a proper definition of "vtuber" for the sake of this board.
My proposal is simple enough - "An entertainer or internet personality who uses software designed to capture a live actor's performance and apply it to a rigged 2D or 3D model (such as through the use of live2D or live3D), who operates on online video sharing and streaming platforms such as Youtube, Twitch, or Niconico."
This of course means no traditional animation and no superimposing an actor's face on top of a real world object, but I feel that such things probably don't fall under the spirit of vtubing anyway and I doubt anyone would be terribly upset that they have to take discussion of such things to /co/ or /tv/.