We’re less than two months away from the release of Battle For Azeroth. While a new expansion is almost certainly a good thing, it does mean that time is running out to complete all your Legion-specific goals, including the multiple rewards that will be inaccessible once BFA drops. The major one is, of course, the artifact appearances you can obtain by completing the Mage Tower challenges for each spec.
Thankfully, Blizzard has made good on a promise and starting today, the Mage Tower will no longer be destroyed in three days’ time — it will remain active on the Broken Shore until the 8.0 pre-patch hits live servers (which should be about a month from now, and is already available for pre-download through the Battle.net launcher). That gives you plenty of time to get the artifact appearances — which will be available as transmog options in BFA if you have earned them — before they’re gone forever.