I'm sorry - but any article discussing Vedanta without referencing the Brahma Sutras is merely a joke. The only way to gain a clear perspective on the development of Vedantic thought through the ages is to start from the beginning and work onwards.
The idea of Brahman as being a universal reality is present and central even to Upanishads that predate Buddhism (Brihadaranyaka, Jaiminiya and Chandogya, for example, date to the late Vedic Brahmana period which predates Buddhism).
In contrast, dualistic sects of "vedanta" can all be dated to India's medieval era and are mostly associated with Vaishnavism:
Dvaita was founded by Madhava (1218-1317)
Bhedabheda was founded by Chaitanya (1486-1584)
Visishtadvaita was founded by Ramanuja (around the 11thc entury AD)
Also, your article confuses Dvaita (monotheism, absolute dualism) with Visishtadvaita (pantheism, also described as qualified nondualism).
Dvaita Vedanta (“dualistic Vedanta”) school of Hindu philosophy, attaining moksha results in the atman recognising itself as part of an even greater being, known as paramatman, an aspect of Brahman. Ultimately, an individual can only attain moksha once all of their karma has been experienced, and they have no more desire to be reborn.
as opposed to the Dvaita concept of being with Brahman, separately, as a part of paramatman.
recognition of the true self, as in Dvaita Vedanta
This is not Dvaita. Dvaita recognizes five fundamental, *eternal* differences:
1. Between the individual soul (Jiva) and God (Vishnu).
2. Between matter and God.
3. Among individual souls
4. Between matter and souls
5. Among various types of matter
Dvaita is a monotheistic philosophy where souls do not merge into any supreme being - souls are instead predestined to end in heaven or to be damned in hell eternally. Another class of souls reincarnate forever.
This concept of anatta has certainly had an influence on later Hindu philosophies. In Advaita Vedanta (“non-dualistic Vedanta”), moksha is attained through the recognition of the true self, as in Dvaita Vedanta. However, the true self is then further recognised as being no different from Brahman itself. It is understood that the concept of individuality is illusory, and that all things are Brahman. The state of moksha is described as being one with Brahman, as opposed to the Dvaita concept of being with Brahman, separately, as a part of paramatman. Advaita Vedanta, like Buddhism, makes no distinction between self and reality once release from samsara has been achieved. However, unlike Buddhism, the concept of atman is welcomed, and is seen as being an intrinsic part of the nature of Brahman, rather than a delusion created by a devolved consciousness.
Your description of Advaita in this paragraph is also very misleading. Atman and Brahman are synonymous in Advaita. There is no such thing as "being one with brahman" in Advaitic thought, simply because there is nothing to be one with brahman. Neither is there any such thing as one's atman - whether before or after moksha. In fact - strictly speaking, in Advaita there is no such thing as moksha, reincarnation, self or samsara at all.