Not quite, though that is a valid issue now that you bring it up.
1: The new “five tap” herbs are a recent, direct boost to multiboxers, which makes their presence far more notable than it was before Legion.
2: Azsharan Herbs - For the first time as far as I can remember, all of our herbs for all of our potions come from one pretty small zone that is easy to scour as a multiboxer. Coupled with the issue outlined above, this makes the presence of multiboxing herbalists far more noticeable than it was before.