Martin (1992: 437):
In writing, the use of macro-Themes to predict hyper-Themes, which in turn predict a sequence of clause Themes is an important aspect of texture; and texts which do not make use of predicted patterns of interaction in this way may be read as less than coherent.
 The field of Martin's discourse has shifted here from building a theory of spoken and written language to prescribing the use of his model for the writing of coherent texts (pedagogy). Removing Martin's re-brandings, this sentence becomes:
In writing, the use of introductory paragraphs to predict topic sentences, which in turn predict a sequence of clause Themes is an important aspect of texture.
 A text that is restricted to this pattern cannot develop, because it must always revert back to the same point of departure. On the model of Daneš (1974) — the source of the notion of hypertheme — there are three main types of thematic progression:
- a preceding Rheme becomes the next Theme;
- a repetition of the same Theme, the first appearance termed a 'hypertheme';
- a progression of derived Themes
For a text to develop, New information has to be introduced — in the Rheme in the unmarked case — and later taken as the point of the departure (Theme) in a subsequent clause, thereby providing the context for the introduction of further New information.
 Consider the likelihood that a text that doesn't develop would be 'read' as coherent with respect to its context of situation.
Note that here Martin provides his own intuition of what unidentified readers might regard as 'less than coherent'. See the related post Misrepresenting Hasan's Work On Coherence As Formalist.