I guess it's been more than a month since nokia have roll out face unlock update and other few features in china and few other countries but for India they rolled out only one update how much time will they take to give and update related to the same as there competitors have already face unlock in the market like.xaomi and one plus etc. Looking forward for nokia's consistency as they said there android one phones will get updates on regular basis.
The logic behind requiring to scroll up is that suppose you just helx your phone to see the time/Ambient notifications, and it automatically gets unlocked.. that would prove really irritating. And hence you need to scroll up!
For me, it certainly is a good feature