No he's just not paying attention. The wanted quests are built into both the leveling guides and the "Zandalar Forever" achievement guide. They aren't in the rep guide because they are not repeatable and by the time you hit max level they should be done. You'll also notice the rep guide doesn't contain every single possible completable quest that rewards rep. It is designed to focus on repeatable objectives, world quests, large quest lines, and missions.
Keep in mind that these quests are optional, and are not necessary to continue leveling and capturing companions. They are also account-wide, so if you complete the quest chain on one character, you will not be able to complete it again on another. However, any progress that you've made will be saved and you can pick up where you left off in the quest chain on another character. The dailies that you've unlocked will also be accessible by all your toons.
When it comes time that the body and mind have been prepared for the ultimate task, the potential demon hunter enters into a summoning circle surrounded by a binding rune. In the middle of this summoning circle, a single demon is called forward and the potential demon hunter is forced to fight for their lives without any help from the outside. The demon in question that is summoned is not influenced by the summoner, but the potential demon hunter within the circle might influence the demon that is summoned by a particular hatred or wish for vengeance upon a certain type of demon. If the potential demon hunter is successful in killing the summoned demon, they must then devour the heart of the creature as well as drink its blood. The binding of the demon’s soul to the demon hunter is extremely powerful, one in five surviving the ritual. As well, the demon’s flesh is extremely difficult to keep down, as if it tries to sear the inside of the body and crawl its way back up the throat of the potential demon hunter. After devouring the heart of the demon slain, each demon hunter is given a vision of the Burning Legion, witnessing the horrors of their enemy for themselves, ending with all potential demon hunters gouge out their own eyes. In the wake of the ritual, almost all successful demon hunters pass out either due to sickness, shock, exhaustion, or overwhelming fatigue.
Felguard: The shocktroopers of the Burning Legion, always seeking out the greatest threat in any particular battlefield. Crazed berserkers, the Burning Legion’s generals have to do little more than trust in their instincts and unleash them upon the battlefields. Demon hunters who bind themselves to the soldiers of the Burning Legion would no doubt become more physically brutal, broad, and capable of withstanding inhuman pain.
Succubus: In the same vein as the imp avoids harm, the succubus is known for slipping in and out of sight on the battlefields, attacking when least expected, and relishing in the pain delivered to their opponents. In the same vein, both pain and pleasure enact a power to the succubus. To the demon hunter bound to a succubus, this might showcase itself with a particular knack for invisibility spells, turning pain into power, and even an affinity with the use of charm spells.