Exactly. It might for example make (business) sense for Google and Facebook to round up every single ML PHD and just keep them busy so they don‘t work for anyone else. That way other companies are dependent on them and they keep resources from competitors. I actually love the Silicon Valley (HBO Show) analogy of engineers hanging out on the roof being „unassigned“.
The rooftop thing was a "rest and vest" situation. Different from keeping talent busy. Something Microsoft did by letting their top engineers build a brand new OS that was never meant for market. Forgot its name, Singularity OS?