This time I was too slow; anyway, took me enough efforts to type it:
Not being a developer, I can't give you first-hand information. But in general: "implemented" often means more or less "completely", or more verbose, "... up to the point that the quest is available which will teach you the basics and give you the crafting book". Often you may be able to obtain ingredients already a little earlier, but won't be able to handle them with something else in your mind.