Blizzard has now added an option for brand-new level 60 Evokers to pick up their Covenant directly in Shadowlands, without having to go through the covenant campaign!
Threads of Fate is being removed as a leveling option through Chromie Time’s Realms of Death, but this put new Evokers in the position of having to go through the entire zone campaigns of Shadowlands to pick up a Covenant. This has been fixed.