My issue with it is that, just as Riyah mentioned, the population is going to decrease by a lot, and I think putting relic weapons behind this one content was a huge mistake. It might not seem that way now, but think: If you decided today that you want to have the Heavensward relic weapon but the "Light farming" could only be done in the Diadem, would you still do it? Because that would require you to do it by yourself.

Eureka is okay, but is far from being a "longevity" kind of content, and I worry that many many people will be even more discouraged to do relic stuff due to how solo-unfriendly this content is.

But, is it confirmed that this IS the relic weapon equivalent on Stormblood? Because it's so weird to not have a dedicated quest to the weapon, and to me it's seems like Eureka is more like the Palace of the Dead "get yo fancy weps here" equivalent, than the actual relic weapon quests.