As you are aware, System76 is now developing their own Ubuntu-based distribution called Pop!_OS, which the company wants to ship by default on their computers. Just like Ubuntu 17.10 (Artful Aardvark), on which the first release of Pop!_OS will be based, System76 own distro will be using the GNOME desktop environment by default. Right now the distro is in Alpha stages of development, but it looks like System76’s development continues to add various improvements to Pop!_OS and the GNOME desktop environment, including enabling autodiscovery of URLs for CalDAV and CardDAV, which requires patching of the GNOME Calendar, GNOME Contacts, GNOME Online Accounts, and Evolution Data Server components.