Apparently there are two separate issues. One is the timing assembly making a sharp scraping sound at startup and the second is the vvti pulley system rattling at startup.
From what I know the timing chain has a guide in it which makes the scraping sound at startup and it is not the tensioner (I could be wrong here).
I have a 2016 GLi Auto (1.3) with about 75000 kms on the clock and NONE of the above sounds. Since it has had no special maintenance or care other than timely changes of oils and filters, the only thing I have done with it is to always use PSO 10w40 oil.
So I am assuming that this particular oil was doing a good job till now. Lets see how much further the engine will continue without developing the noises.
It seems that if you do have the sound, then the problem has established itself already. Not sure if it is worthwhile fixing it.
So this may be good advice for people with newer cars or rattle free cars: ALWAYS USE A GOOD OIL!
My humble 2 cents on the matter!