I started other mentioned topic Ghost won't start after upgrading to v4.0.1 and I just resolved my issue!
If it helps anyone, I resolved my issue by completely uninstalling my failed installation and installing a fresh version 4.0.1 Fresh install failed to run automatically, but after manually running sudo systemctl start ghost_your-blog-com everything started up just fine.
If I had another chance, I’d try to just execute above command before uninstalling.