I think 7.2 is a good time to reroll if you are thinking about doing it.

Besides the fact that they are adding new Artifact Knowledge levels which will help you with your empty weapon, they are also adding gear vendors for nethershards in 2 varieties: 850 and 880.On top of that, they are rebalancing dungeons and raising their base item levels: 825 in normal, 845 in heroic and 865 in base mythic.They are also upping World Quest item levels to 865 and some world quests will drop tokens that will upgrade a piece of your class hall set to 870.Crafted gear is also getting a boost in base item level to 835 with a max ilvl of 875. The obliterum forge is also being opened up to everybody for free, without having to do the long quest chain.Class balancing won't happen until just before ToS releases, which is still months away. So if you are rerolling, it should probably be because you don't enjoy your current class since you have no idea which class is going to get buffed or dumpstered next.