This is it, the first CU for Skype for Business 2019 is now available for download and install from http://www.microsoft.com/downloads/details.aspx?familyid=de77f3bc-efd5-4dab-a2fb-81e2894b0937.
The list of all fixes is available from the KB 4470124 https://support.microsoft.com/kb/4470124/.
It is worth noting that the SfB Control Panel is also getting a refresh, getting ride of Silverlight. The ‘new’ control panel is at his early stage, meaning not all the capabilities are available.