Regarding exploratory content not being present in EW, it seems clear from the acquisition method of that expansion's relics (which in the prior two expansions were tied to the exploratory zones) that it was just a cutting corners/minimal effort measure.

You see this in other aspects of the game as well in DT, such as the hyped up double dye channel. Many in-game sets (including WHM/BLM ARR Artifact Armor set) were skipped over getting their second channel despite funnily enough the dyeable cash shop items all getting second dye channels.

I was also hoping(coping?) that DT, being the first expansion where Hrothgar/Viera are finally fully implemented with both male and female available; that the new headgear for Artifact Armor would work on them. Sadly they were left out again. The future in regards to the hrothgar/viera hats front seems bleak, because if anything we seem to have regressed in having gear work with particular racial features. We've been seeing Miqote ears being lopped off of gear for a bit, but now its not only extended to their tails being chopped off on some gear, but also elezen and lalafell are losing their ears as well.