Notes:
Is there anything that distinguishes Agile methods here? I don't think that anyone advocates methods that contradict this principle.
Perhaps there is a school of project management to which this is a reaction – but I don't recognise it.
In any planning method that I've looked at overtime, or other excessive demands is seen as the result of a planning failure. I.e. It may be needed to address an unforseen crisis but should only occur in exceptional circumstances.