Gunbreaker/Dancer Primal weapons from before Shadowbringers.

[Seraphor]

Because the game is constantly adding new sets of weapons it eventually becomes unfeasible to release new jobs with weapons from every set ever released. When ARR released for example, there were I think 3 primals that rewarded weapons. So it wouldn't take many resources to make sure a new job's weapons was added to that content after the fact.

But now there are 20+ trials that reward weapons, not to mention Deep Dungeon, dungeon, tomestone, and crafted set weapons. The amount of work it takes to make sure all jobs have weapons from this back catalog of content is vastly higher than it was in ARR.

It might be a bummer, but eventually the task reaches critical mass and is no longer worth the effort for every job released.

But to stop all previous weapons is a bit of a blow.
If they kept to something like 'only the one previous expansions primals' or 'only ARR primals as a baseline' then it'd be more acceptable.