With Dragonflight Season 4 now live, players already clearing their weekly objectives have discovered that the Timewalking Weekly Quest cache contains lower than intended item level rewards! Although listed as item level 493, it only appears to be awarding 395 gear.
Although an item level 493 reward is displayed, the cache is currently giving out only 395 gear.
This is almost certainly a bug and one that Blizzard typically seeks to compensate players for, but players are advised to avoid turning in their weekly A Burning Path Through Time quest a fix has been confirmed.