Good news, today Microsoft has released the latest Exchange version – Exchange 2019.
It is being available through the Volume License or MSDN.
That said, you can deploy Exchange on Windows Server 2016 or Windows Server 2019, but it is highly recommended to deploy Exchange 2019 with Windows Server 2019.
Exchange 2019 also supports installation on Windows Server 2019 Core.
To know more about what’s new and what’s removed with Exchange 2019, go there https://docs.microsoft.com/en-us/Exchange/new-features/new-features?view=exchserver-2019