There's quite literally a Falador massacre that took place a few years ago. If Jagex doesn't want to have in-game lore to clash with real-life "lore" they could also opt to hit us with a new Saradomin quest (Death of Chivalry follow-up)that brings us to a basement where mass genocide of some sort happened. Making us unlock another tree through questing like the Darkmeyer, Priff and Ritual Site tree.
(Because lets be real, Manor Farm having one isn't related to known lore either.)
Edit: Manor Farm does have lore behind it, but so does Falador!
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