If it is truly rattling on startup then no, that is not normal for this motor. We traded in our beloved 2014 Jetta SE 1.8TSI for a 2020 Jetta 1.4 TSI (with timing belt) for this reason. The 2014 started exhibiting signs of timing chain trouble so we jumped ship before it was too late. It has 60K miles on it when we traded a couple months ago. The early 2014 1.8's had an old style chain, it was updated with a new part mid 2014. So your bothers 2016 has the updated part. Not saying it couldn't fail also, especially if there was lack of maintenance.
