So we're in agreement in rejecting monotheism. (I reject it for other philosophical reasons too.)
But this article is about mystical, monistic spirituality such as what you find in Eastern traditions or in New Age or New Thought movements. Does that spirituality entail altruism and submission to social conventions or nihilism and amorality? It's supposed to entail the former, but I suspect a real case of it would entail the latter.
I wrote a dialogue between the Marquis de Sade and the Buddha that gets at this problem.