This decision also highlights one of the main themes of the series—systemic vs. individual bigotry and how individuals can uphold or work against the status quo.
Wyldon takes Jonathan’s compromise as permission to continue his bigotry. In turn, Joren and the other pages take Wyldon’s treatment of Kel as endorsement of their own bullying.
Wyldon barely allows Kel to stay, despite her exemplary performance, and openly treats her poorly— pages take their cues from him. Many are openly misogynistic and sexually harass Kel. Vinson takes it to the point of committing serial rape and assault of other women in the castle and city. Joren holds onto his own bigotry so tightly that he can’t survive his Ordeal. They make their own choices, but they were certainly influenced by Wyldon.
In addition to reinforcing misogyny, Wyldon mistreats other pages who don’t fit his ideals of knighthood—Neal in particular. Once again, Joren and his crew respond to this, bullying young pages as they please. Had Kel not stepped in and rallied her friends against it, how many other young pages would have been bullied out of knighthood or turned into bullies themselves?
There’s a great moment at Joren’s trial, where Joren basically says he was dojng Wyldon a favor in trying to get rid of Kel. Wyldon objects—he didn’t want that. But it’s too late. It doesn’t matter what he says. His mistreatment of Kel set the tone, and Joren and many other pages followed.
The same holds true for King Jonathan. His treatment of Kel—and his own daughter, for that matter—sets the tone for how women are treated in general. He is in the wrong.
And Pierce doesn’t really give Jon and Wyldon of them a chance at redemption, or any credit for Kel’s success.
Wyldon retires in shame. He is—quite explicitly—a failure at his post. Though he learns and grows, his failure remains.
Jon doesn’t win Kel’s sincere loyalty, which Raoul rightly points out as a major loss. In fact, when choosing between allegiance between King Jonathan and Kel, Alanna, Raoul, the King’s Own, almost an entire generation of knights, Wyldon’s squire, and Jon’s own son all choose Kel, some to the point of treason.
Kel succeeds in spite of them, mostly due to mutual support with other people/ creatures rejected by the system, and the steadfast support of other women. And it’s through that solidarity that Kel effects change in the system from below, unlike the men that maintain it from above.