Bug 1893910

After upgrading some packages today I've noticed these messages and since I don't like them I want to report them:

Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-xfce4\x2dnotes\x2dautostart-autostart.service, it is hidden.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-xscreensaver-autostart.service, could not find TryExec= binary xscreensaver: No such file or directory
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-xfce4\x2dsettings\x2dhelper\x2dautostart-autostart.service, only Type=Application is supported.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-xfce4\x2dvolumed\x2dpulse-autostart.service, only Type=Application is supported.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-at\x2dspi\x2ddbus\x2dbus-autostart.service, only Type=Application is supported.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-nm\x2dapplet-autostart.service, only Type=Application is supported.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-xfsettingsd-autostart.service, only Type=Application is supported.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-pulseaudio-autostart.service, startup phases are not supported.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-xfce4\x2dclipman\x2dplugin\x2dautostart-autostart.service, it is hidden.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-gkrellm-autostart.service, it is hidden.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-xfce\x2dpolkit-autostart.service, only Type=Application is supported.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Exec binary 'reset-xorg' does not exist: No such file or directory
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-Xorg\x20Reset\x20Output\x20for\x20NVIDIA-autostart.service, error parsing Exec= line: No such file or directory
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-QuiteRSS-autostart.service, it is hidden.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-xfconf\x2dmigration\x2d4.6-autostart.service, it is hidden.
Nov 02 11:07:58 localhost.localdomain systemd[3734]: Not generating service for XDG autostart app-alarm\x2dclock\x2dapplet-autostart.service, it is hidden.

And then later again with fewer messages (why?)

Nov 02 23:12:00 zen systemd-xdg-autostart-generator[377630]: Not generating service for XDG autostart app-at\x2dspi\x2ddbus\x2dbus-autostart.service, startup phases are not supported.
Nov 02 23:12:00 zen systemd-xdg-autostart-generator[377630]: Not generating service for XDG autostart app-xfce4\x2dnotes\x2dautostart-autostart.service, it is hidden.
Nov 02 23:12:00 zen systemd-xdg-autostart-generator[377630]: Not generating service for XDG autostart app-pulseaudio-autostart.service, startup phases are not supported.
Nov 02 23:12:00 zen systemd-xdg-autostart-generator[377630]: Not generating service for XDG autostart app-xfce4\x2dclipman\x2dplugin\x2dautostart-autostart.service, it is hidden.
Nov 02 23:12:00 zen systemd-xdg-autostart-generator[377630]: Not generating service for XDG autostart app-xscreensaver-autostart.service, could not find TryExec= binary xscreensaver: No such file or directory
Nov 02 23:12:00 zen systemd[377621]: Queued start job for default target Main User Target.
Nov 02 23:12:00 zen systemd[377621]: Condition check resulted in Mark boot as successful after the user session has run 2 minutes being skipped.
Nov 02 23:12:00 zen systemd[377621]: Started Daily Cleanup of User's Temporary Directories.
Nov 02 23:12:00 zen systemd[377621]: Reached target Paths.
Nov 02 23:12:00 zen systemd[377621]: Reached target Timers.
Nov 02 23:12:00 zen systemd[377621]: Starting D-Bus User Message Bus Socket.
Nov 02 23:12:00 zen systemd[377621]: Condition check resulted in Sound System being skipped.
Nov 02 23:12:00 zen systemd[377621]: Starting Create User's Volatile Files and Directories...
Nov 02 23:12:00 zen systemd[377621]: Finished Create User's Volatile Files and Directories.
Nov 02 23:12:00 zen systemd[377621]: Listening on D-Bus User Message Bus Socket.
Nov 02 23:12:00 zen systemd[377621]: Reached target Sockets.
Nov 02 23:12:00 zen systemd[377621]: Reached target Basic System.
Nov 02 23:12:00 zen systemd[377621]: Reached target Main User Target.
Nov 02 23:12:00 zen systemd[377621]: Startup finished in 104ms.

What systemd is doing and why?