Pro Linux published an article about the new features and how Collabora Online Office is integrated into EGroupware:

EGroupware GmbH has released a new version 17.1 of its groupware. The open source solution enables collaborative editing of documents within Collabora, variable customization of the appearance, an additional option for encryption and new functionalities in various sub-applications.

The complete article from the 15th of November 2017 in german language can be found on the website of the website of Pro Linux.