I wanted to expand on this post with more of Loy's writing. Therein Loy noted that Buddhism has to get a new story because it arose in the Axial period where dualism was rampant within all religions. It expressed in Buddhism as the strict dichotomy between nirvana and samsara, otherwise known as the two truths. He said:
"Like other Axial developments, Buddhism basically rests on cosmological dualism. Instead of God and the created world, it’s samsara versus nirvana. […] On the popular level of understanding, however, Buddhism devalues this world as a place of suffering, craving, and delusion, and the goal of Buddhist practice is to transcend it."
I'd say it was far more than just "on the popular level" but at the root of shentog and even rangtong, but not as pronounced. This thread has explored that in depth. So I'd like to introduce here Loy's chapter "Beyond transcendence: A Buddhist perspective on the Axial Age." I just skimmed it for now so will read carefully and report. It begins with this:
"The implication is that nirvana is not that attainment of some other reality or transcendent dimension but realizing the true nature of this world, right here and now" (156).
I'd note for now that Loy is in the zen tradition, infamously part of shentong. It's one thing to speculate on the "true nature" of this world but another to fully 'realize' in some meditative state of consciousness (satori). even if we interpret that state as 'natural' (samsara) and nondual. More later.
Update: As previously stated, the Axial Age was about a strict dualism. In Loy's essay he discusses the conditions that caused this split: the emergence of abstract rationality from more concrete operations. Another aspect was the rise of individuality, so we might even say that this was an egoic rationality. It was expressed in all manner of hierarchical relationships of domination: men over women, human over environment, reason over body. Loy argues that we need to move beyond this dualistic stage via the “spirituality of evolution” (169). This entails moving beyond a sense of our separate self to a nondual relationships with something beyond it like others and the manifest world. He offers the example of the Buddha as a path in that direction but does not elaborate. And it is here that this thread indeed elaborates on how many forms of Buddhism maintain the metaphysical dichotomies of the Axial Age. So even Buddhism needs a "new story" in his words.
He said: "Shunyata is not 'nothingness' but the formless potential that describes awareness prior to identification with any form" (166). I suggest that this fully present nondual 'awareness' (shentong) still retains the metaphysics of presence, which itself is part, but yet subtler example, of the same kind of dualistic metaphysics above.