Cyborg checked for a second time and lo and behold, there were really aren't any records regarding Midoriyama Satoshi. Sure he had that footage from where he fought against the Slime Alien and he also has his footage from the initial match on the first day of school in USA. But aside from all that, there was no information on him. It's as if he hasn't even registered to the SAO System, not once.
"How could someone with such a powerful superpower not have any trace in the SAO?" Primal asked Cyborg who also didn't know the initial reason. Even they have a few records in the SAO after being identified as a superhero... or maybe their case was different since they were teenagers who involved themselves in petty crimes. Usually, people like that would have a permanent record in the SAO archives and all of their superpowers are specified.