In most Mahāyāna Buddhisms, including most Chinese Buddhisms to the exclusion of Chan, the Mahāyānamahāparinirvāṇasūtra’s identification of 4 ennobling qualities of the dharmakāya, (1) purity, (2) eternity, (3) ecstasy, and (4) identity, is taken as a neyartha Dharma, specifically for the purpose of correcting nihilistic interpretations of the 4 marks of existence, which are opposite the 4 marks of the dharmakāya.
Some Chinese and Japanese Buddhisms take the sūtra literally.
A questionable methodology for correcting nihilism
Mahākāśyapa Bodhisattva asked the Buddha to speak: “Bhagavān! I from today start in obtaining samyagdṛṣṭi. Bhagavān! Until now, we all entirely abided in mithyādṛṣṭi. Bhagavān! In the twenty five existences, is there ātman definitely?” The Buddha said: "Kulaputra! Ātman, prompt and exact, is tathāgatagarbha in meaning. All sentient beings in entirety have the Buddha’s nature, prompt and exact, ātman is it’s meaning. Thus so, ātman’s meaning is, from root proceeding onwards, constantly without limit under kleśāḥ covered, therefore sentient beings cannot obtain sight of it.
(V Dharmakṣema Parnirvāṇa Vaipulya T374.407b6)
On the matter of identity vs selflessness in Mahāyāna, IMO we can consult Venerable Vimalākṣa’s commentary, here, on Venerable Nāgārjuna’s ātmaparīkṣā, or ātma-analysis, which can be found at the 18th section of the Mūlamadhyamakakārikā (only a short snippet of the ātmaparīkṣā is in that thread linked to).
Then we can discuss, if it please you and others here, the relation of this line of thinking to the Buddhism of the EBTs.