If Enzo Maresca doesn’t perform well next season, then what happens to other Chelsea coaches will definitely happen to him. Chelsea doesn’t have patience with their coaches, if a coach doesn’t perform well, he will be sacked immediately. They want a club that will change Chelsea's performance instantly, not one that will improve the club's performance gradually. So let’s see how Enzo Maresca will perform. I am sure he will do everything possible to improve Chelsea’s performance because he won’t want what happened to other Chelsea coaches to happen to him also.
Of course, Chelsea must have a big target for the next season. They seems to target to finish in the UCL zone. If Enzo Maresca fails to improve the position of Chelsea in EPL table since the early of the season, he may be fired in the middle of the season. It is true that Chelsea management very often changes the coach. Even if Pochettino can improve the performance of Chelsea, Chelsea management still fired him. So no doubt Enzo Maresca will be fired as well if he can't show positive progress on Chelsea performance. Honestly, I'm quite doubtful that Enzo Maresca won't stay in Chelsea until the end of the season.