The community has compiled a list of undocumented changes that went live in the Dragonflight pre-patch. Check it out!

Classes

Sense Undead now has a sound effect when you activate it. (Source)

Creatures

Aetheil, Yuyu, and Rips were added to Orgrimmar. (Source)
Druid treant received a new model. (Source)
The health of creatures has increased drastically, especially noticeable for pre-Shadowlands content. (Source)

Items

Orcs now properly wear shoulder armor. The gap has been fixed. (Source)
Class-specific Engineering recipes from Sunwell can be learned by any class now. E.g. You can learn a Druid-only schematic on a Hunter. (Source)

Mounts

Mammoth mounts have a new summon sound. (Source)
Divine Steed has a new sound when summoned. (Source)

Professions

Milling for Draenor Garrisons now requires Draenor Inscription. (Source)
Mining has a new sound effect. (Source)

Raids

Aspects in the Dragon Soul raid use the new Dragonflight models. (Source)
A motion sickness peon was added to Dragon Soul. (Source)

Spells

Paladin’s Exorcism has a new sound effect. (Source)

Torghast

While doing Torghast through Threads of Fate, you get reduced XP from solving Chest puzzles (-50%) and rescuing Souls doesn’t grant XP anymore(was around 1k). (Source)

UI

Minimap tracking and Profession icons have been updated. (Source)
The Looking for Dungeon eye (icon) turns red when you spam-click on it. (Source)

Source: Reddit

If you noticed a change that isn’t on the list, let us know in the comments and we’ll add it.