"Judgment is compromised when decision rights are ambiguous.
The useful word in this quote is compromised. In a planning call where the timeline is already promised, it points to the part of the decision that will not be solved by effort or optimism. That is where good teams get surprised.
In a planning call where the timeline is already promised, you can do everything “right” locally and still make the global system worse. The seams are where the cost lands. You see it in estimates that harden into commitments because the numbers look clean.
Eliot Jaques is a reminder to keep it concrete. Make the boundary explicit: the next action, the non-action, and the condition that forces a revisit. Make it specific enough that a peer can disagree.