Quoting Adam Borowski (kilobyte@???):

> Generally, all desktop environments but hardly anything else in Debian
> Jessie require systemd for an important part of operation.

In testing of Debian Jessie and querying of package metadata, I found
these Debian 8 'Jessie' DE metapackages require package systemd via
sundry package dependency chains.

gnome
gnome-desktop-environment
gnome-core
mate-desktop-environment
mate-desktop-environment-core
cinnamon
kde-standard
kde-full
razorqt
task-lxde-desktop
lxde

However, FWIW, these did not:

xfce4
e17 (not actually a metapackage)
fvwm-crystal
gnustep (w/wmakerWM package)

I subsequently upgrade my test VM (running in VirtualBox) to Debian
Squeeze without systemd-dependency problems. At that time, it employed
just Window Maker without any DE. I haven't yet bothered to test or
check DEs in Debian Squeeze since then, mostly because I (personally)
continue to see no value in DEs.

On a very quick check appears as of these metapackages newly introduced
in Debian 9 Squeeze are among those _not_ adversely affected:

task-lxqt-desktop
lxqt

I'll also mention in passing that people interested in DEs needn't
necessarily use the metapackages. Nothing wrong with installing only
what you actually want, on an a la carte basis.