Also patch notes
I actually posted a bunch of stuff a few pages back, the main misconception is because the title for the class in japanese is Knight, and people assume that means it's not holy, but it's Knight in english, as opposed to the japanese word for knight(Naito instead of Kishi), which inherently implies a different type of knight which in past FF generally meant having access to White Magic, and the term Paladin is actually also used on all official sources in japanese for the class. Plus most skills being in english and having the same name(Divine Veil, Holy Spirit, Clemency, although Hallowed Ground isn't called that in Japanese), the fact it could use Conjurer cross class skills back in the days and Rage of Halone with refers directly to a divinity.
So overall, it's a massive misconception just based on the fact that the name of the class is Knight but not understanding that naming something in english has significance.