Yes, this is just a very tiny point overall and it is very situational.
I raided the whole addon as Fury and was most of the time able to dps the boss while moving, but there are times where it may be hard.
In my raid we do have a lot of melees, which makes it i.e. a bit complicated on Myhtic Tyrant with all the fire patches.
And you can dot the boss before some moving is incoming and you can also pool some AP. So technical, it is easier on a ranged to still do some dps than on a melee. If i lose contact to the boss as a melee, i do 0 dmg and with all the aoe effects, which is definitly a point as you should avoid them.
But as i already said, thats not a big point, just an addition to the other points which are way bigger.
And i don't want to say fury is the worst regarding to survival in raids, but balance is definitely not the worst (by ease).
And in legion i will presumably main my Boomkin, so it is not whining about fury