Considering how many times they implented some sort of content "unfinished" isnt the first time even with Eureka.
When squadrons got implented you basically were able to recruit, level and sent them on missions for the scrolls.
Now we can run with them 7? dungeons and earn achievements/emotes. Considering how "dead" squadrons are, I would also expect Eureka to get more features over time.
The only question still stays though. What did take so long to create Eureka and delay it from last big patch? Basically they fused diadem 1.0 and 2.0 into one; yet once you get your 3 sets of relic done; all minions and mounts/glam etc; will eureka stay dead or still be active?