The situation of Owncloud support has been significantly improved over the past months in Fedora and CentOS (EPEL):
- https://fedoramagazine.org/owncloud-updates-coming-soon-fedora/
- https://lists.fedoraproject.org/archives/list/epel-announce@lists.fedoraproject.org/thread/JLU2EZ2LZYSIECFGZBZRFJ3ZN2CZCEBO/
I assume that Fedora / EPEL will switch to Nextcloud, if that is where most developers will be. Similar to Mysql => MariaDB.