Some key text (my hyperlinking added):
[The Buddha said, "My concept of the]Tathāgata-garbha is not the same as the ego taught by the philosophers; for what the Tathagatas teach is the Tathāgata-garbha in the sense, Mahāmati, that it is emptiness, reality-limit, Nirvana, being unborn, unqualified, and devoid of will-effort; the reason why the Tathagatas who are Arhats and Fully-Enlightened Ones, teach the doctrine pointing to the Tathāgata-garbha is to make the ignorant cast aside their fear when they listen to the teaching of egolessness and to have them realise the state of non-discrimination and imagelessness. I also wish, Mahāmati, that the Bodhisattva-Mahāsattvas of the present and future would not attach themselves to the idea of an ego [imagining it to be a soul]. Mahāmati, it is like a potter who manufactures various vessels out of a mass of clay of one sort by his own manual skill and labour combined with a rod, water, and thread, Mahāmati, that the Tathagatas preach the egolessness of things which removes all the traces of discrimination by various skilful means issuing from their transcendental wisdom, that is, sometimes by the doctrine of the Tathāgata-garbha, sometimes by that of egolessness, and, like a potter, by means of various terms, expressions, and synonyms. For this reason, Mahāmati, the philosophers' doctrine of an ego-substance is not the same ... as the teaching of the Tathāgata-garbha. Thus, Mahāmati, the doctrine of the Tathāgata-garbha is disclosed in order to awaken the philosophers from their clinging to the idea of the ego, so that those minds that have fallen into the views imagining the non-existent ego as real, and also into the notion that the triple emancipation is final, may rapidly be awakened to the state of supreme enlightenment. Accordingly, Mahāmati, the Tathagatas who are Arhats and Fully-Enlightened Ones disclose the doctrine of the Tathāgata-garbha which is thus not to be known as identical with the philosopher's notion of an ego-substance.["]
That's why these folks who say,"See? Buddhism is Biocentrism!" don't quite know what they're talking about, regarding the "Mind only" schools, including Zen Buddhism, have considered "Buddha nature pervades the whole universe."
The notes by the translator say the next section "strangely found its way" to its present position. I quote it in its entirety; I think it actually belongs where it is...
The personal soul, continuity, the Skandhas, causation, atoms, the supreme spirit, the ruler, the creator, —[they are] discriminations in the Mind-only.
While there is an Awareness of which we can be aware which transcends the "small mind" (I assume that's not trademarked!) to make further discrimination about Awareness - about which Biocentrism is one such discrimination - is to be dealing in different matters and views than what Buddhists in Mind schools have referred to as Mind, Buddha nature, or (as I've done right here) Awareness.