When you try to backup Exchange Server 2016 servers with Veeam Backup and Replication 8.0, you will not able to recover Exchange 2016 server application elements.
After a "successfully" backup up of an Exchange 2016 Server with Veeam Backup and Replication v8.0 in Application Mode you will not be able to recover E-Mails or databases with Veeam Explorer for Microsoft Exchange. Furthermore you won't see any Exchange Server 2016 item level restore points under the Veeam Backup and Replication console. Also the transaction log file trunction on the Exchange server to did not work.
The reason is, that veeam "Historically, [...] needed 2-3 months since RTM to add support for new major releases of 3rd party software. Which makes v9 the first opportunity [...] to deliver support for Exchange 2016 (unless it has lots of braking changes, which will postpone support further)."
Veeam is planning to introduce the backup of Microsoft Exchange 206 Server in the next version of Veeam. This will be Veeam Backup and Replication v9.0