KBS has not officially banned Park Si Hoo from their station.
All three terrestrial stations (MBC, KBS, SBS) declared that they'd be waiting until the end of the investigations to decide if they would ban Park Si Hoo or not. KBS ultimately decided not to ban him, saying, "Park Si Hoo was not included on the most recent list of names banned from KBS broadcast. It's because his case was dropped and the investigations have come to a close. Because of this, he's not included on the ban list."
However, just because he's not on the ban list doesn't mean he'll be appearing on the station again. KBS said, "Even if he's not banned, it's still up in the air if he'll ever appear on a broadcast again in the future. He created a social disturbance, so the viewers' opinion of him is not positive."
Currently, Park Si Yeon, Lee Seung Yeon, and Jang Mi In Ae are all still pending on their bans as their trial is still going on for their propofol case. Kim Yong Man is also under the same pending status because of his illegal sports gambling.
Go Young Wook is currently temporarily banned. After his appeal hearing and future hearings, his ban will become confirmed.