ownCloud does not have a feature for automatic or for initiating the installation of new version releases. Moving to a new release can be achieved by installing a new updated Amahi package or installing the new ownCloud release manually.
Like a lot software in the Open Source world when there is a new ownCloud version release, any Third Pary applications written by a "third party author" may not work as expected with a new release. It takes time for the third party authors to update their software components applications to work with the new release. Third Party applications will need to be "restored" from backups or re-installed.
Reinstalling a new Amahi package is a safer practice.