"New game plus - quests will have no rewards..."

[Niwashi]

Biggest being it's LEVEL 80 content.

If so, that's a bigger issue than whether it does or does not have XP rewards. One of the big reasons (maybe not the biggest, but still a fairly major one) for people wanting to replay the story is returning players wanting to review where they left off and what was happening before they forge ahead into the next segment of their story. Besides just players who've been away from the game a while, it's a concern that can also apply to anyone who's spent a while on alt characters, alt jobs, crafting, or whatever other features. Going back and replaying the last few quests that you'd finished would be a far better way of getting back into the story when you're ready to continue it than anything we have available now.

Ideally, this should unlock as soon as you complete your first MSQ or class quest, and let you at any time thereafter review any of the MSQ/class/job quests that you've completed so far. I don't quite see any point in SE's decision to divide it into "chapters" (whatever that is), when it's already subdivided into quests. But having it unlock a chunk of several quests at once as soon as you finish that block could also work (even if not quite as well as being able to go all the way up to the last MSQ you'd completed).