While I agree with your point, I think the article more accurately describes that they need constraints, rather than discipline.
They need to be told no, to be given chances to understand that their behavior has considerations outside of just how it makes them feel. They need to be exposed to challenges like being bored or any other feeling so they can learn how to self-regulate their emotions when adverse situations present themselves.
Children without constraints seem unlikely to want, or be competent at leaving the safety of their parents protective bubble.
They need to be told no, to be given chances to understand that their behavior has considerations outside of just how it makes them feel. They need to be exposed to challenges like being bored or any other feeling so they can learn how to self-regulate their emotions when adverse situations present themselves.
Children without constraints seem unlikely to want, or be competent at leaving the safety of their parents protective bubble.