Sec. V: a self-reflexive song that recalls the Prologue’s plea for forgiveness. But it also responds to—and corrects?—that plea, offering a defense (mild yet bold?) of these elegiac songs and cries. I think, here, of the well-worn trope of a poem that stands in for the loved one, securing the loved one’s being long after their death. (Shakespeare’s “this gives life to thee.”) But Tennyson twists this trope; his songs wrap him (and his grief) up; they do not preserve A.H.H. but, rather, the grief, the feeling of loss, the strongest evidence of a treasured relation.
Sec. VI: a hint of anger here, responding to efforts (made by others) to redirect his grief. He imagines fellows and friends who, like him, will look back and realize that at the very moment of the loved one’s death (or, perhaps, a moment afterward) that they had been preparing to meet them: thinking fondly of them when they were already gone. I want to say that structure of the section resembles the effect/structure of the In Memoriam stanza itself, but perhaps that’s not quite right. Will think on it more.