1. An apostolic exhortation is not, by its very nature, a non-magisterial document. It is the content of a papal document that reveals its magisterial relevance, not its name or category -- no one doubts Familiaris Consortio, the John Paul II exhortation on his synod on the family, was extremely relevant in sorting out important Magisterial points. Amoris Laetitia itself does not say that it is not itself magisterial: what it says, in its highly explosive paragraph 3, is that the Magisterium does not need to be invoked or suffer intervention to sort all Catholic questions. On the other hand, this same paragraph opens up a Pandora's Box of decentralization of the Magisterium, creating a centrifugal force which can ruin Catholic doctrinal unity.
2. Saying Amoris Laetitia is not a big deal, and not magisterially relevant is simply not true. The present Pope and his successors will not act as if it were not magisterially relevant, and bishops on the ground will certainly invoke it in their own Magisterial pronouncements. Amoris Laetitia will certainly have its place in future editions of the Denzinger and in any future revision of the Catechism of the Catholic Church.
3. Francis, with some of his previous documents, but particularly with Amoris Laetitia, introduced a kind of "uncertainty principle" in Catholic doctrine and hermeneutics on morals, marriage, and family life, and that itself is magisterially relevant.