Yeah, but creative teams apparently think they need to put new characters in every movie.
Replacing Chekov means putting a new navigation officer. I guess if they wanted to, Jaylah could assume that role if she has graduated already, but I see her being more interested about Scotty's job than Chekov's.
I don't recall any major new characters (other than the villain) in TSFS. Saavik and David were both returning characters. And Saavik was going to return for TUC, too, until they couldn't get the actress back. Generations also went straight to Lursa and B'Etor instead of creating new characters. It's not at all unheard of to bring a character back instead of making a new one.
And replacing Chekov does not need to mean putting someone at his exact bridge station. She could easily work in engineering with Scotty. Or she could be at an engineering station on the bridge. Or she could be in a role she doesn't want to be in as part of her training - you could have plenty of fun with her and Scotty arguing about whether it's useless for her to train in positions she never intends to fill.