Hi AdityaTumuluru, welcome to AYP forums!
On the contrary, the AYP lessons do mention how to prepare the body and mind for pranayama, and it is found throughout the lessons in the proposed schedule by which new practices are taken on, as well as a repeated emphasis on general principles of self-pacing.
Lesson 43, for example, mentions that spinal breathing needs to be followed by deep meditation, while a short, normal, or enhanced asana set is suggested prior to spinal breathing.
The practices were selected because they are powerful, so it is not surprising that you too confirm this observation. Spinal breathing begins with visualization, tracing the central route along a specific pathway clearly outlined and explained, root to brow. Also, spinal breathing, along with the other practices, are themselves preparation for the rise of ecstatic conductivity, in which some unbalance and associated symptoms are expected to occur to some degree such as between the ida and pingala.
AYP is made to be as flexible as possible so that you can take on elements from it while sticking to a path you find most suitable. Just keep in mind that doing so could be at the expense of its built-in optimization of opening and self-pacing.