Lack of autosave is a backwards step.
Also your email said you can still save to Microsoft OneDrive and Dropbox but inside the app I can only see a Dropbox tab but no tab for OneDrive :-(
We are sorry for the inconvenience.
The Acrobat Reader DC on Android or iOS have not supported the integration of Box or Microsoft OneDrive yet.
You may use this link : Adobe Acrobat for Android - Feature Request/Bug Report Form to request for this features.