I don't think this is accurate. The genalogical framework predates Reynolds' by decades and will continue long after the 'nuum is nothing but a faint memory. Rock is constantly looked at in terms of genealogy: blues>rocknroll>metal>punk>new wave etc... reggae too ska>rocksteady>reggae>dub>dancehall... this extends to art criticism as well.
You may be right in saying that the challenge is to find new methods of analysis, but I think the 'nuum is small fry when it comes to contributing or imposing to what is, by tradition, a dominant mode of analysis and criticism of music and art in general.
perhaps so, it cannot be denied that that approach is pervasive in most music critique / documenting. the question would be how inevitable it was that it would become quite so entrenched in relation to a form that in many ways was a radical departure from the past
but either way you're certainly right in saying that the real issue in my post is whether or not the zeitgeist / straightjacket exists, not whodunnit