Satoru was fine after Suguru "left". Sure there was the initial shock after everything went down but he was Satoru Gojo the strongest jujutsu sorcerer alive. He didn't need someone like that, someone who turned to the very things that they were working to extinguish. It didn't upset him or make him easily agitated, it didn't keep him up at night, it didn't make him feel physically ill and it definitely didn't make him avoid everyone...