What is centralized transport?
If you already have heavily invested in your on-premise mail gateways and other infrastructure and you plan on moving to Office 365, Exchange Hybrid is the way to go in a long haul. When you have Exchange 2016 configured for Hybrid Setup with Office this where it come.
So Why Centralized Transport?
It all depends on your business requirements, and if you don’t then you are good with regular setup routing via Office 365 , let’s cloud manage it for you. IF YOU DO HAVE such as regulatory and compliance requirements and even for other purpose where you want you emails MUST route through your on-premises infrastructure then you need to configure it this way. In this video I will walk you over how does it really work.
Route mail through the on-premises organization for both on-premises and Exchange Online organizations