I don't know, that guy has many videos on Youtube and says he is a Nirmala.
No, and I don't know anyone by that name. My point of view is that, on the basis of historical example, the Sikh Gurus married within their own caste group, i.e. they made a point of marrying only those people who were 'halal' for them within the parameters of respectable Indian cultural norms. Furthermore, the 10th Guru said he was a 'shatri'. Both of these historical facts seem to indicate that caste was not rejected in the way that many people might think. Also, if you look at Sikh people today, there are fringe groups such as the modern Deras comprising Dalits, the Chamars and other Mazhbi groups. There is an understanding that these people are not true Sikhs, and I suggest this is because they would not have been eligible to join the Khalsa at the time when the Khalsa was still extant (in original form). The 10th Guru also has a detailed history of his Sodhi family that's included in the Sikh sacred texts. So what this indicates to me is that the 10th Guru's 'Khalsa' may have been a fraternity to which a minority of people could aspire to join, on more or less the same conditions as those that applied to the traditional akharas of sadhus, on which example the early Sikhs modelled this fraternity.
The sadhus likewise reject the temple and household brahmins, because they are 'dead' to their household lives in the service of their Guru. They are/were in disciplined groups, they don't have any possessions, they have no fear of death and they eat and sleep little. This is a model of obvious benefit to any militant order so it makes some sense that the Khalsa would have been modelled after this pattern. Whatever the case may be, it seems clear that the Khalsa was not supposed to be a householder, and that not every Sikh was supposed to hope to become a Khalsa. The householder Sikhs would have continued their ancestral rites (including sacrifices into the havan while reciting Vedic formulae in the case of khatris, Bishts, etc.), and would not have been expected to hold to the creed of the renunciate Khalsa as summarised in some of the quotes from Akaal Das here on this forum. The popularisation of Khalsa was encouraged for political reasons first by the British then by separatists, and led to its apparent demise (notwithstanding recent attempts to reconstruct nihang heritage etc.). The whole model of initiation depends 100% on authenticity of lineage - when it's lost it's lost forever.