The release notes notes these Exchange-related fixes:
- – Fixes stability of Mail
- – Addresses an issue that caused certain events in a custom reoccurring meeting to drop from Exchange calendar
- – Fixes an certificate error that prevented configuring an Exchange account behind a third-party gateway
- – Fixes an issue that could cause an organizer's Exchange meeting notes to be overwritten
- – Resolves an issue that prevented some Calendar events from automatically showing as “busy” after accepting an invite.
So, you want to test and accept this iOS update before giving it the green light for your Exchange environment.