Well yes, but then someone under 16 can't marry, join the army, have sex etc. The concept of in parentis locus would surely still exist ?
Speaking of which, I am sure that this change has been rigorously thought through to ensure we don't see glaring anomalies where people can vote, but not but alcohol, or someone can vote but gets treated as a "child" for the purposes of criminal law. I'm not venturing into other threads, but I would be surprised if real considerations like that are at the fore of discussion.