I’m not sure if this applies to every timewalking event which had dungeons rotated in and out as part of 9.1.5, but for Wrath timewalking I was not offered the timewalking event quest upon entering either Utgarde Keep or Forge of Souls. Both of these dungeons are “new” to the Wrath TW rotation. Meanwhile, I was auto-offered the event quest upon entering Gundrak which was an original in the Wrath TW rotation.