Blizzard published early patch notes today before the 9.1.5 PTR goes live, detailing all the changes coming with the new quality of life patch that was announced last week.
Legion Timewalking won't be a part of the first test build once the PTR goes live later this week, meaning players will need to wait a while before they are able to test the new system.
Six dungeons will be available to complete on the Legion Mythic+ week, and players will be able to speak to Ta'hsup in Oribos to acquire a "Timeworn Key".
The dungeons available are Black Rook Hold, Eye of Azshara, Darkheart Thicket, Vault of the Wardens, Neltharion's Lair, and Court of Stars.
Legion Timewalking Mythic+ Dungeons Will Count Towards The Great Vault But Award Shadowlands Loot
Legion dungeons will have separate affixes from Shadowlands dungeons, and potentially have the old system of tyrannical and fortified on the +10 level like it was in legion although this is not confirmed.
The end of dungeon loot will be the same item level that current mythic+ dungeons are, and the gear can be upgraded with valor points up to the cap of 246, although will not be able to go higher.
Dungeons completed will count as progress towards players' weekly great vault, although players will only have the chance to obtain Shadowlands gear at the end of the week.
When the patch goes live, players will have two weeks to participate in Legion Mythic+ Timewalking before it joins the Timewalking rotation along with all the other expansions before it.