Vorrede

The "Vorrede" starts with "wether": not rhetorically, but as a quoted, i.e. a given question which is out of discussion. If the reader accepts, he is in, if not, he rests outside. There is no passage from the surrounding world to the topic. However, the argument is one of the most general ones: "Erkenntnis", knowledge, and the working with it, the job of reason. Kant is writing in a period when reason and science were central to the reading public, and, as topics, did not need any particular introduction, while Wolff, seventy years earlier, in his introduction still had explained the role of reason and virtue.
Note the plain words Kant is using for Philosophy:
"-geschäft" and "Bearbeitung" could stem from a plumber's workshop.
The "Vorrede" can not be considered a "Paratext", it is immediate philosophical consideration. In order to understand the "Danksagung", we needed to know something about the professional situation of Kant, for the "Vorrede", the reader can ignore who Kant was. And: De nobis ipsis silemus.