Regarding email synchronization via Exchange protocol, Apple also knows that you may see an error message saying 'Cannot Send Mail. The message was rejected by the server 'if your mail account hosts on Outlook.com, Office 365 or Exchange Server 2016 running on Windows Server 2016.
In the update notes, Apple does not provide much information about iOS 11.0.1. The download and installation summary only states that iOS 11.0.1 'has bug fixes and some improvements on iPhone and iPad'.