The light novel author who was arrested for tax evasion was likely Mamare Touno, who wrote Log Horizon. He was arrested in 2016, and was put under suspended arrest (if he goes three years without bad behavior, he won’t go to prison). That’ll be a theme going on, by the way.
The Weekly Shonen Jump author who was arrested when the mangaka was a kid is probably Mitsutoshi Shimabukuro. He was writing Seikimatsu Leader den Takeshi when, in 2002, he was arrested for paying a 16-year-old girl 80,000 yen to have sex with him (he claimed he didn’t know the prostitute he hired was 16). His manga was cancelled when he got arrested, but his arrest was suspended and in 2005 he resumed Takeshi, following up with Toriko after. It’s heavily assumed that Shimabukuro got leniency with Shueisha for his actions because Eiichiro Oda, author of One Piece, is a closed friend of his and vouched for him, though there is no concrete proof of that.
The author who is mentioned to have been arrested for sexual assault during COVID is likely Tatsuya Matsuki, author of Act-Age. In August 2020, he was arrested for allegedly approaching and inappropriately touching two female middle school students in June of that same year (reports said he was riding around on a bike, going up to girls and molesting them). Act-Age was cancelled almost immediately after, and Matsuki was, of course, put under suspended arrest.
By that logic, the mangaka who was arrested for CSAM at the beginning of the chapter was the most recent case: Kenya Suzuki, author of Please Tell Me! Galko-chan. In December 2021, one of his close friends posted on Twitter that he went missing and wasn’t seen for a week, which caused people around the internet (yours truly included) to worry about his well-being. As it turns out, he was safe… in jail, because he was arrested for importing child porn from Germany. Kadokawa immediately cancelled Galko-chan and Suzuki was - say it with me now - put under suspended arrest. He’s still out and about now,
posting on his Twitter and trying to get more new work.
There’s also Nobuhiro Watsuki, author of Ruroni Kenshin, who was also arrested for possession of CP, but that was in 2017 so I doubt the manga is referring to that. I think.