As the linked paper states in it's opening phrase - there are several interpretations of the idea of 'herd immunity' - so that immediately means there is room for confusion when the idea is discussed:

Some authors use it to describe the proportion immune among individuals in a population. Others use it with reference to a particular threshold proportion of immune individuals that should lead to a decline in incidence of infection. Still others
use it to refer to a pattern of immunity that should protect a population from invasion of a new infection. A common implication of the term is that the risk of infection among susceptible individuals in a population is reduced by the presence and proximity of immune individuals (this is sometimes referred to as ‘‘indirect protection’’ or a ‘‘herd effect’’)

Obviously there are millions of people on Earth who speak about these subjects, so it is not really possible to take into account every interpretation and every application of the phrase that has ever been uttered. However, in my experience, it has been fairly common to hear the phrase used as a way to suggest that entire populations can be protected from disease as a result of a certain percentage of individuals receiving vaccinations - including those who are not vaccinated. In other words, there is an inference of a magical ability for real immunity to develop even in those who are not vaccinated - hence 'herd IMMUNITY' as opposed to 'herd exposure reduction', which would be the more accurate phrase to describe the type of result described by the study on the Japanese population that is referenced.

Having looked through the actual paper that is referenced, it is clear that they are not describing a total immunity to disease (even among the unvaccinated) as a result of sufficient vaccination, rather they are simply describing that the disease incidence is reduced enough as a result of vaccination, that transmission is reduced in general and so the unvaccinated also benefit.

I am not disputing that this is a likely outcome of a mass vaccination program and I don't think that the doctors that I am referring to would dispute that either.

So to reiterate, my conclusion here is that the term 'herd immunity' is misleading and commonly misused - usually to promote vaccination programs.

For a variety of Doctor's comments on vaccine science (who are exposing commonly denied aspects of the situation), I suggest listening to the ones in my earlier post on vaccines and vaccine injury.