I think they are linked but I would define the cultural shift as something separate, canceling of people is a symptom / result of this cultural shift so they a

I think they are linked but I would define the cultural shift as something separate, canceling of people is a symptom / result of this cultural shift so they are linked. However there are other aspects of this shift that fall outside of cancel culture. For example the fact that a platform like twitter can have a CEO that publicly supports the rejection of the 1st amendment is also a symptom of this cultural shift, a few decades ago that would not have been possible, in fact it likely would have resulted in high level board meetings and a PR disaster in the 80's and 90's if a CEO of a large public company would have stated opposition to free speech. We has a nation (the US) have lost desire to uphold the cultural principle of free expression, the law has become a needed check on this cultural shift but sadly the law only survives as a check for 2 maybe 3 generations, if we do not do something to shift us back to being a culture that respects free expression the law will fall to the new culture of non-expression or controlled expression and a new dark ages will emerge