The reality is that you can never know where the new jobs come from. But any growing (either in the sense of population or productive output) society will need more work done.
Consider the factory robots from the article: they automate a bunch of people out of a job and just a few people now do what 100 did before. But now the machine shops that make the parts to build that automation have more work to do, they need to buy more CNC machine tools to keep up and (a few) more people to run them. So the CNC tool supplier sells more machinery and now needs more sales reps, field installers & repair personnel. The company importing the CNC machines from Japan hires more people to handle increased demand, etc.
You have to look at the entire value chain of a process to see the ripple effects and even then it's only visible in hindsight.
Existing factories that aren't yet automated and employ all 100 workers already depend on upstream providers. They already need parts and processes, they already need the tools the human workers use, they're already courted by sales people. Not to mention, they depend on uniform services, on-site nurses, healthcare providers, maybe cafeteria workers. Because their spaces have to accomodate humans, their factories have to have certain sized doors, passages, have to meet a bunch of safety standards. They have to lease land for parking lots, hire security guards to make sure cars aren't getting broken into, etc.
I think its kind of naive to just point to a shifting supply chain as if that addresses the problem.
Consider the factory robots from the article: they automate a bunch of people out of a job and just a few people now do what 100 did before. But now the machine shops that make the parts to build that automation have more work to do, they need to buy more CNC machine tools to keep up and (a few) more people to run them. So the CNC tool supplier sells more machinery and now needs more sales reps, field installers & repair personnel. The company importing the CNC machines from Japan hires more people to handle increased demand, etc.
You have to look at the entire value chain of a process to see the ripple effects and even then it's only visible in hindsight.