When it comes to technology companies, product renaming and refocus is often inevitable. This recently occurred with Citrix as they have moved away from the "Xen" prefix and have simplified their product portfolio naming to make them easier to understand. For example, the new name for XenApp is "Citrix Virtual Apps" while XenDesktop is now "Citrix Virtual Desktops". These are the two primary products from Citrix that are used to deploy ArcGIS Desktop and ArcGIS Pro as virtualized applications. At the same time, Citrix is changing the associated product versioning and moving to a year and month format, for example:
YYMM = Year and month when the product or component released. For example, a release in August 2018 appears as 1808.
Citrix recently released the latest version of Citrix Virtual Apps and Desktops utilizing these changes and the current release is "Citrix Virtual Apps and Desktops 7 1808.2". This means that XenApp/XenDesktop 7.18 was the last release of the 7.x releases and the new version of "Citrix Virtual Apps" appears to be what XenApp 7.19 would have been and not a major upgrade, though Citrix is constantly evolving their products.
Though the naming changes are helpful for understanding product purpose, I don't anticipate much of an impact from these changes at a technical level. Over the last few years Esri has been certifying multiple Citrix releases and the most recent "certified" Citrix release for ArcGIS is XenApp/XenDesktop 7.17. It is likely that the new "Citrix Virtual Apps and Desktops" release, or a subsequent release, will be certified with the next major ArcGIS release so look for updates on the associated ArcGIS system requirements pages.
