Thanks @creativeblue
From the whtiepaper:

Stage 3 - Beta version - 2019 Q2 ...
...
Decentralization of Master Node network. Developed and tested smart contracts will enable autonomous system - Worker Nodes will be able to become Master Nodes based on certain parameters and proof of stake mechanism.

Those "certain parameters" are still a year or so away. I have not found anything final about this and NOIA does mention that it will adapt its long range plans based on how things progress.

I am unsure where you are going with PoS and PoW. What I can say is that PoS allows a major player with a lot of money to enter a blockchain investment easier than with PoW.