Comment (including rationale for any proposed change):
the information for the user is important not the change in presentation...
Information that is conveyed by variations in presentation of text is also conveyed in text, or the informations can be programmatically determined.
SC 1.3.1 and 1.3.4 have been combined to read "Information and relationships conveyed through presentation can be programmatically determined or are available in text, and notification of changes to these is available to user agents, including assistive technologies." This wording ensures that it is the meaning conveyed by the presentation that must be programmatically determined, and allows the author to indicate the meaning in text if it is not feasible to do so programmatically. The How to Meet document describes this in some detail.