Hey @ferviron thanks for bringing this up. I am in the same boat as you. Most of all fantastic job from whoever is involved in porting 3.22.
I believe KDE Plasma will depend on systemd quite soon as well. At least this is what their official position is. Maybe it will be soft dependencies for a while, but not long. Anyways I tried KDE Neon recently but don't find Plasma to be nowhere near as polished and intuitive as Gnome - heavier, lots of bloatware, all in all not my cup of tea.
As for Budgie, they extended the roadmap for the 11.0 iteration to second quarter of 2017 so yes it will definitely take a while. Besides my favorite feature from Gnome, the Activities are missing anyway.
The way things are going I think anyone hooked up on Gnome will eventually switch to systemd for the sake of progress.
The rest of the crowd, especially those fans of tiling managers would probably hang on for quite some time as there is now an increasing number of non-systemd distros.
Time will tell...