Apparently the Keystone Master achievement with the Awakened Mindborer reward is still available in pre-patch, contradictory to the information in Blizzards Time Runs Short: Battle for Azeroth guide.
So if any of you are still missing a few of the dungeons, now might be a good time to time them on +15.
It would also be nice if people could confirm this, since I can’t test it myself (since I already got the Feat of Strength).
Others can try to get it too if they are missing it. If it’s going to be reverted there is nothing lost. Mythic plus is a lot easier in prepatch than it was. +15s are not challenging at all.
Apprantly the article on it actually says its removal is on the release of Shadowlands, so techniqually not a glitch and appears as far as i know is susposed to be enabled.