Ghost Rider was spun into the Supernatural realm the moment he was first introduced when he sold his soul to the devil/mephisto/the devil again (f**king continuity be damned with this character) He fought plenty of people with supernatural elements, and even raced against The Grim Reaper.
The 90s version did the same thing multiple times. I am not sure what you even mean. Surely the midnight sons was not his first entry into the supernatural since Ghost Rider is a part of it by origin!