Update 12/13/2016: Please see the December 2016 Quarterly Exchange Updates blog post for updates on this subject.
We wanted to raise your attention to an issue that some customers have reported running Exchange Server 2016 on Windows Server 2016. Crashes of the IIS (W3WP.exe) process have been reported causing instability of Exchange Server on Windows Server 2016. The Exchange team has worked with the Windows team to isolate the source of the problem. An update for Windows Server 2016 will be made available to resolve this issue. Microsoft recommends that customers delay deploying Exchange Server on Windows Server 2016 until this update is made available. For the latest guidance on known issues, please consult the Windows Server release notes on TechNet.
When there are updates on this, we will update this blog post.