Wrong. The negative effects of the word nigger are greater than ever these days. That's why you call it the "N word." Did you even notice that? They don't even say that word on the news anymore. Why is that if the negative effects of it are being diffused now?
It is because totalitarian, Orwellian Newspeak is becoming stronger, so that if you use it, you have to expect punishment.
I'm happy to hear, in the video, that the youth ignores this and uses the N-word. It means, newspeak is not yet that powerful.
In fact, the meaning of words changes all the time, and if a word is invective or positive is what changes often very fast. Take a look at this forum, and you can easily find out that "my friend" is becoming more and more invective. Another actual example is that "partner" becomes an invective in Russian language - completely spontaneous, but with the political background that Putin and other Russian politicians refrain from using invectives against NATO and US politicians and continue to name them "partners". Some time one could observe an increasing ironical use with "partners" used in quotes, but now I have seen already several clearly derogative uses of "partner" without any quotes.
This happens in a quite natural way. There are general rules of polite behavior, which forbid to use invectives. But there is also the natural wish to use them. The natural reaction is that one replaces the invective itself by another word, which does not have such a negative meaning. But there is also a context of this use, and this context remains aggressive, even without the invective itself. So, given that people are able to feel this context, they see the word without negative meaning used as a replacement or euphemism for the invective. This is copied, and the former normal word becomes an invective. And this is essentially unavoidable. because it is the elite, the upper class, which is bound to polite behavior much more than the lower classes, which uses this new, negative meaning first, but it is also the upper class which sets the trends. While the lower class continues to name an idiot idiot, the upper class starts to name him intellectually challenged, and then the lower class follows the new trend.
This may be not universal, sometimes it is the lower class which starts to use a word in a derogative meaning, while the upper class continues to use it in a positive way. At least this is what I observe with the German word "Opfer", victim, which became a typical lower class immigrant slang invective in Germany already about 1995, but still remains used positively by the politically correct upper class.
The reverse change, from negative to positive, also happens, but seems more difficult. The typical way is that an invective starts to be used in small circles as an indication of close friendship - I can name you a .... because we are good friends, and you know that I don't want to insult you but use it as a joke. Another way is "the society names us ..., but so what, we f.... the society, and use this word for ourself, because there is nothing wrong with being a ....". The first way will remain restricted to small groups. I have to be part of the group, else I'm not allowed to use the word. This seems to be part of the use of the n-word among black youth. The second way can lead to acceptance by the whole society - but only if combined with acceptance of the whole formerly despised group by the whole society. This is what happened with the German "schwul" for gay, and AFAIU also for "gay" and "queer".
Whatever, there are many ways how the meaning of a word changes, and all they prevent Orwellian Newspeak, because they all prevent the totalitarian control of the language, which works only if the meaning of the words is fixed, and if one can control it by forbidding bad words.