I meant Eureka / Bozja style content.
There have been numerous commentaries on the issues with those zones, especially the fact they get a hell of a lot harder to complete once the expac ends

This from ( h/t ) Packetdancer

While I mostly agree, I'm still going to judge SQEX a bit on this one.

I know folks who only just got to level 80, who would really like their Resistance relics (because pretty weapons!), but who have found there isn't enough population in Bozja now for them to complete things like Castrum Lacus Litore or Delubrum Reginae. And I think having rewards tied to that content that people coming along later will want, but no other way to keep the content alive is at least mildly problematic once the initial waves are past; as you yourself note, people got the rewards and then noped out because there was some other newer reward they now wanted to grind towards -- or because they went "Okay, got my stuff, now I'm going to take my break and go play Other Game for a couple of months until the new raid tier drops." or whatever.

And while Discords like Primal Forays and Eurekan Explorers and whatnot exist—and I've directed the folks I've encountered to those sort of resources—someone trying to just do that content in the game is not necessarily going to know to go look for those.

So I do think SQEX could demonstrably do a little better at future-proofing some things here and incentivizing people to keep the older stuff alive for the newer players following along behind us: add weekly challenge log entries for critical engagements, put Delubrum Reginae into Wondrous Tails, make some of these sort of things give current capped tomestones if you run them with a level-capped character, etc.

I mean, they demonstrably know this does keep older content alive, because they incentivize specific instances of older content in that way already with Wondrous Tails, as well as incentivizing filling whatever older content needs people with daily roulettes.
Also ( h/t ) TaleraRistain

I'm really hoping these last two expansions have made it crystal clear to them that artificially propping these zones up with a highly desired weapon instead of making them places that people actually want to go to and do things in is not an effective way at all to future proof their content.
Id love to do CLL and Delubrum..but thats dead content now , very few are doing it on Zurvan or across OCE, Eureka unless you are dedicated is also an issue.....so as my learned colleague above has said, it hasnt been future proofed.

I CAN see what you mean, but then the question then is : will this content then viable afterwards.

Eureka is also ( sigh ) bot riddled.