Please no more "Inspired by real world culture"

[Loggos]

It sure is a...choice...that one of the first things you list is cannibalism when talking about (indigenous) tribes.

Also, I'm rather confident the reason why there are no major story-relevant factions in this game that engage in cannibalism has nothing to do with "real world sensibilities" and much more with age ratings and general marketability.
(I don't know if in some corner of the world some NPC may reference or engage in cannibalism but I don't think any of the major tribes, incl. in ARR, practice it? I don't remember the Ixal, Goblins, Sahagins etc. eating each other.)

FF14 does have some dark themes. But overall the game still wants to appeal to a wider audience with a somewhat positive, colourful, optimistic vibe. Always has. They've always walked the tightrope of idealism and overly positive tropes like the power of friendship mixed with serious plot points.

We have piracy with human trafficking themes in ARR and that's still in the game. We have human sacrifices to revive a dead lover in Tam-Tara hard. Yotsuyu's entire storyline. In Shadowbringers one of our NPC friends turns into a monster and we have to kill her in a dungeon. The people of Eulmore eat the flesh of sin eaters (and some sin eaters used to be human, so I guess there is your cannibalism in a round-about way).
Amaurot.
The Werlyt side quests.
In Endwalker we have cutscenes with people turning into and being killed by dynamis monsters (forgot their names). In the lvl 95 dungeons a mother and her children turn into monsters right before our eyes and we have to kill them.
In the Garlean zone we find the dead bodies of the two NPC girls we tried to help as an explicit quest point.
In the FF4 arc we have a cutscene where marauders are on their way to explicitly rape women in a village (Zero having a flashback showing how she couldn't stop them).

In Dawntrail one of the tribes (as it seems to be so important that it's a tribe) has had cruel breeding practices to produce two-headed super lizards which meant forced marriages, forced pregnancies (iirc, though please let me know if I misremember, too tired to go through the cutscenes rn) and eugenic-style selection of infants. We literally visit a mass grave related to that.
In Solution 9 people eat each others' souls while their dead are stored in a cloud that relies on genociding other civilisations and harvesting their energy to exist.

Up until and including this expansion the story hasn't shied away from dark and even marcabre themes. Dawntrail dropped the ball in many ways but with the writing being so terrible across the board there is no real way of saying what the rationale for certain world building and story decisions was. Like I said, think of that whole eugenics tradition re: Bakool Jaja. That's certainly not a plotpoint that "plays it safe". It just didn't make Tural any more interesting because it was written so terribly.
We can't rule out that in the hands of another writer Tural would have been better-written, more interesting and more layered while also not reproducing the oldest and tritest stereotypes about "tribes".