The concern is about what happens to people who are no longer employable if we cannot create new jobs for them? Will everyone be happy when a majority of the population depends entirely on charity and hand outs?
Honest answer, I don't know. But I wouldn't have known what would happen to the ~30% of the US population that worked in farming 100 years ago or the 90% that were working as farmers in 1862 [0]
Jobs aren't really created by a central authority. They just kind of appear as people find better things to do with their time/talents. The future may not follow the past, but so far we've been okay.
