You know what this is?
Of course, this the Yaru theme, but it’s running on my Cosmic install, as the default theme in the default ubuntu session!
Yaru-theme is already available in cosmic.
To get it by default, everything is ready, the set of patch (settings the correct themes by default, ensure our ubuntu GNOME Shell mode picks the Yaru G-S theme, setting it as a default to gdm, installing the right set of packages on the default iso and for upgraders) is available here: https://bugs.launchpad.net/ubuntu/+source/yaru-theme/+bug/1783571.
However, we need first to have the Main Inclusion Request approved which is opened at https://bugs.launchpad.net/ubuntu/+source/yaru-theme/+bug/1783600.
As soon as this is proceeded, expect the theme to land as default really soon