I don’t mind fighting the Arathi if it is like the original Scarlets being manipulated by or embracing the void/demons.
There may not be a dearth of light users, but traditional Warcraft paladin/priestly orders seem pretty absent unless they are neutral. Representation for faction-specific organizations for paladins and priests (Cult of the Forgotten Shadow included) has always been kind of odd.
Blood Knights, Sunwalkers, Prelates/Zandalari Priests, Priestesses of Elune, and Lightforged have the most distinct identities by comparison. But that still leaves a lot of races out.
Without Turaylon there isn’t a prominent Classic Warcraft human paladin hero either. After him, I can only think of Lord Maxwell Tyrosus and Captain Travard filling that role (though lacking the legacy connection).
Another thing that contributes to this sense of absence is that there isn’t much focus on the lawful good light factions’ reactions and or confrontation of the evil light users.