Mounts move out of your bags into their own window, and bags gain a reagent slot.
- Warcraft Tavern saw an extra bag slot and calls that fifth slot a reagent bag slot.
- Their 19 Sep professions guide says the reagent bag sits beside 5 basic bags.
- The same writeup says transmog lets you save an appearance without holding the item.
Unconfirmed the bag count, since the two writeups count the slots differently, and which mounts the window holds.
Source Warcraft Tavern, from the BlizzCon floor demo, 16 Sep 2026.