The approximate year of the purported split between an Ali faction and an Abu Bakr faction is not a 'correction' of a post about when Sunni Islam began.
I am demonstrating my argument is correct: that Sunni identity emerged centuries later.
Your sources say nothing about this as they are like the simplified version of the atom they teach to children in science class - a simplification to make something far more complex to make it easier to understand for those without a greater depth of knowledge.
A selection of proof from this thread
for my statement that mistakenly attempted to correct:
1. Sunni Islam did not appear in history fully formed; but that it emerged through a complex historical process, a process which yielded widespread Sunni self-awareness no earlier than the late 9th century
2. The name “Sunni” abbreviates a phrase that better clarifies the Sunni movement’s ideological parameters: “ahl al-sunna waʾl-jamaʿa” (the People of the Tradition [of Muhammad] and the Community). As with Shiʿism, however, it is imperative that we not regard this tradition as emerging fully formed at the time of Muhammad. On the contrary, it took time to develop, often in relationship to a series of legal and theological disputes, certain answers to which would emerge as “orthodox.” Although many of these answers would at a later date be taken to have existed at the time of Muhammad, there is no clear evidence that they did.
3. One common mistake is to assume that Sunni Islam represents a normative Islam that emerged during the period after Muhammad's death, and that Sufism and Shi'ism developed out of Sunni Islam.[19] This perception is partly due to the reliance on highly ideological sources that have been accepted as reliable historical works, and also because the vast majority of the population is Sunni. Both Sunnism and Shiaism are the end products of several centuries of competition between ideologies. Both sects used each other to further cement their own identities and doctrines.
4. Sunni Islam is defined not by its allegiance to a particular individual (e.g., Ali and the ahl al-bayt) or institution (e.g., the Imamate), as Shiʿism is, but by following one of the four authentic schools of law that are envisaged as representing the true elaboration of Muhammad’s Sunna. These schools took generations to develop
5. The [9th C] caliph wanted the ulama to submit to his will and acknowledge him, as caliph, as the religious authority to guide all believers. One of the ulama who directly opposed the caliph was Ahmad b. Hanbal who, by any standard, was pivotal in the development of Sunnism... The ashãb sunna highlighted their accounts about the correct behavior of a Muslim rather than a caliph's opinion about what a Muslim should believe. Thus the first and most important tenet of Sunnism was established in opposition to the caliph's will and a momentous step was taken in the crystallization of Sunnism as we know it.
Is there any of the above you consider to be false or misleading? If you can't identify anything false, then you accept the truth of my statement that Sunni Islam emerged centuries later, and which you have studiously avoided addressing.