Doctrine by Footnote?

I have only read the first 28 pages of Amoris Laetitia--and do intend to read the rest "patiently and carefully" as the Holy Father instructs us to in the Exhortation's introduction. Admittedly, however, upon hearing of the controversy stirred up by a few footnotes in Chapter 8, I raced ahead to see what all the fuss was about...as though doctrine could be taught...changed!?...via footnote? But then, am I the only one for whom footnote 4 of Carolene Products came rushing to mind? 

Recall that in US v. Carolene Products Company (1938), the Supreme Court upheld a public health and safety regulation as presumptively constitutional law-making on the part of the federal government as within its power to regulate interstate commerce. (The Court had repudiated Lochner  just a year earlier.) But the Court dropped footnote four, laying claim to other types of legislation for which a more probing scrutiny would ensue. Footnote four would eventually become legal doctrine. 

Of course the parallel between the Exhortation and Carolene Products fails as to the substantive contents of the text and footnotes, and it's inapt to compare the development of doctrine in the the Church with the development of jurisprudence by the US Supreme Court. But what I am struck by is the confidence with which notable Catholics eager to see the full dismantling of the Church's sexual teachings believe they have found their foothold in the Exhortation--and perhaps in the footnotes specifically! (And some Catholics hoping to see tradition upheld have agreed that the debate about the document's meaning takes place in a footnote...with some quite sure of it!) 

Even for a centuries-old faith, this is a first.