With the BoA AK your alt can quickly unlock the new 7.2 traits with just a few WQ's. My alt only has 21 hours, 13 mins, and 36 seconds at level 110. I already have two of my artifacts (druid) at 36 and 37 traits. Its an alt I use for healing but I level at feral and unlocked the new traits for feral because I do WQ as feral. The gear isn't mythic raid or m+ but that is because I have only done lfr, heroics, and WQ for gear.
Since 7.2 (and with flying unlocked) alts are easy to catch up. No matter your goals. Obviously to be the "best" content will take a little longer to gear up but you won't really be a hindrance for current content and will easily be ready for Tomb Mythic if you prepare now.