And people will still not go there. It may be novel at first, but even the people that enjoy it will start to keep away over time, and most people will just flat out not care unless there's loot involved.
Riddles are a great example of one-time-use content unless they have a writer change them up on a daily basis. Jumping puzzles too, to a lesser extent (unless you add dailies for them a la GW2 or gathering nodes at the end of them [expect rage]). The content would need to be truly dynamic to incentivize people to do it continue to do it on its own merit, and even then may need significant rewards to maintain interest.
This should be a more prominent thing, even if I don't believe it would increase zone traffick. And done well. As in incomplete, in-depth, yet potentially tattered journals that FEEL like journals, and not in the GW2 style of "3-second overview of an entire reqion" or the BotW style of "Life's journal (that conveniently happens to only include events of my life relevant to you!)" We have a bit of this withe the notes left by Ser Yumeric's men, Edda's journal, etc. within the dungeons, but you'd expect places like the Sharlayan ruins to have a load of old documents lying around (granted, the Goblins might have picked them clean, but still).
This is somewhat near an idea I had years ago, to make hunts into actual hunts. As in, rather than the monster just popping in a zone, you first start seeing signs of them, injured/dead NPCs on the road, spots of blood, trees knocked aside, scorch-marks on the ground, etc. You would then have to follow the destruction and lure out the monster. Kind of like how S-Ranks are now, but... less obtuse, and with a more sane way of knowing if they're actually available or not.
Unfortunately this would ultimately result in the 'Tedious' variant of encouraging zone participation in that after the first week; people would just stop caring about the journey pretty quick and want to kill the things again. And even during that time, most people would still just go, "I'll wait until someone calls it" rather than getting out there and looking for things... :-/