Blizzard have announced they will be disabling the patch 9.2 set bonuses when the Dragonflight pre-patch arrives, marking them as Legacy. This change arrived relatively quickly and it is not Blizzard’s intention to discontinue set bonuses so quickly after they were implemented in the future. There’s still no official word on when the pre-patch will arrive, although most players assume it will be at the same time as the end of Shadowlands Season 4, on October 25th.

9.2 Sets (Source)

With the initial release of the Dragonflight pre-expansion patch (version 10.0.0), class set bonuses from Eternity’s End (9.2) will be marked Legacy, effectively disabling them in combat.

While it’s routine for us to mark older set bonuses as Legacy, we do not normally take this step so soon after they were acquired. Unfortunately, the extent of class changes coming in the pre-patch is an exceptional circumstance that has led to this decision.

In the future, it is not our intention to repeat this timing when marking class sets as Legacy.

To account for the removal of set bonuses and addition of the new talent trees, game content will be re-tuned in 10.0.0 so that difficulty remains relatively the same.