Microsoft has updated his System Center Roadmap
Microssoft has stopped the Semi-Annual Channel for System Center, see here for details.
The roadmap for “Long-Term Servicing Channel (LTSC)” can be downloaded here (http://download.microsoft.com/download/5/9/6/59602436-C9C5-48A1-B305-827654B9077B/System_Center_Roadmap_EN_US.pdf).
Update Rollups for the System Center 2016 and System Center 2019 will be released at a regular cadence of 6 months. Update Rollups for System Center 2019 will include features and enhancements along with fixes.
Update Rollup 1 (UR1) for System Center 2019 is planned for Q3/2019 and Update Rollup 8 (UR8) for System Center 2016 is planned for Q4/2019