At first, I was wondering that myself, but actually, it’s been documented (not a common occasion with them 
):
Twist Schedule Update
Twist is returning in December with Patch 31.2, the first major content patch after the next expansion launch. It will return for three consecutive seasons based on the Wonders format, so that anyone who missed it the first time will have another chance to experience the twists. More information about the specific rules of each individual season will be shared closer to launch.