Ubuntu 19.04 comes with the Yaru theme and a new wallpaper.
Canonical announced today that Ubuntu 19.04 will reach the end of its life on January 23, asking that all users update as soon as possible.
Released nine months ago, on April 18, 2019, Ubuntu 19.04, called Disco Dingo, was the first version to bring the Linux Kernel 5 series by default. In addition to including the desktop environment GNOME 3.32, a new icon theme, and several updated fixes and components.
Ubuntu 19.04 was released for power users and enthusiasts, so it only had nine months of support. Since January 23, Canonical will no longer release any more updates or security patches, so users are encouraged to update to Ubuntu 19.10 (Eoan Ermine).
"Being a long-term unsupported release (not LTS), Ubuntu 19.04 only had nine months of support, so the end of its cycle is near. As of January 23, this version will no longer be updated”As mentioned by Adam Conrad from the development team
Update now to Ubuntu 19.10 Eoan Ermine
Canonical asks all Ubuntu 19.04 Disco Dingo users to update their installations with its official version or one of its flavors (Kubuntu, Xubuntu, Lubuntu), you can easily update by following the Official guide.
You can easily upgrade to Ubuntu 19.04 and switch to Ubuntu 19.10. The latter is the most recommended for having better performance, remember to create a backup before updating.