There may still be a few bits of systemd installed, but at least init itself is not systemd and cleaning up any remaining pieces should not be too hard.
Two things would concern me:
1 - It is not a systemdless installation. It is a mostly systemd-free installation.
2 - After installing a minimal system and purging the systemd packages, what can be safely installed afterwards? Obviously not Gnome, but how many packages would pull in systemd dependencies?
I do not see this as a viable solution. And of course, it is only temporary. The next release will probably not have even this less than optimal option.
Klingons are fun, but Romulans are the sexiest women in the galaxy.