Blizzard made some Timewalking changes in the Dragonflight expansion.
On the Beta, MrGM discovered some changes implemented for Timewalking that we should see go live on November 29 when the expansion launches.
The first major change is tied to reputation buffs active during Timewalking events. The buffs increase reputation gains by 100% and start working at Level 60.
The second change is related to queueing for Timewalking Dungeons. You must be level 68 or above to start queueing for them.