Blizzard has posted hotfixes for today which includes Legion Raid difficulty tuning.
Hotfixes
Dungeons and Raids
Enemy difficulty has been adjusted to increase relative player power in all Legion raid encounters.
Items and Rewards
Tome of the Tranquil Mind and other similar tomes are now gray items and are no longer usable.
Professions
Fixed an issue where Shadowlands professions could not be trained before level 48 in Timewalking Campaigns.