Well, that has now happened.
The telerobot is made by Anybots, and there's one obvious noteworthy point: the robot just isn't expressive enough. Without more capacity for expression, the robot becomes just an uninteresting prop on the stage. It does have a display, but it's way too small to see the speaker's face.
For telerobots like this the screen needs to be of a similar size to a tablet computer, with face detection used to crop and scale the image in such a way that it's of similar dimensions to a human head. Then I think the experience for users, or for an audience, would be more interesting.
But of course this is just the start, so I expect that in time those ergonomic modifications will come.