These events occur immediately after the meta event cycle restarts but will stall until players complete them.
You need to do the three events in North/West/South that power up the outposts and precedes the Pylon events. Participate in powering up each of the outposts around Auric Basin. The achievements are listed in chronological order. Check the timer here to see which stage the meta event is on so you know which achievements you can do. These achievements are only doable at certain stages of the meta event, which has a repeating timer.