Maybe they are trying to distance themselves from the name 'Watchtower', so it looks more biblical, rather than odd. How many people in places other than the Eurasian Continent, even know what a watchtower is? I've never seen one in North America, except the odd cranulated tower on some of the old KHs.
'Watchtower' magazine is associated with annoying people pounding on your door on Saturday morning. Yet, you may actually LIKE a JW that you work with, as long as they aren't constantly preaching at you, so you may be curious enough to look up their religion. I doubt anyone is curious enough to look up the magazine.