Please tell me, are retainers supposed to reach your wisdom teeth?

Often not: Wisdom teeth are often tricky to provide retainer coverage with a clear tray-type retainer. Because two jaws do not move in a parallel fashion, when teeth are covered with the same thickness material, the furthermost back tooth contacts more prematurely. This is quite true when it comes to a wisdom tooth. Thus, it is common that the retainers reach up to the wisdom tooth but do not extend over it.

Depends: If third molars integral to success and stability of your orthodontic treatment result, they should be retained. Ask your orthodontic specialist for advice as per your personal requirements.