Fils, Mensik, Shelton, and Musetti all still have some more potential to unlock. But considering the age of Sinner and Alcaraz themselves, it's hard to see anyone not under 20 right now being able to reach those heights.
Shelton is a serve bot and some of that has to do with how late he started the sport, it's gonna be tough for him improve with guys who we've been playing the sport as kids. I like Fils a lot but injuries scare me with him. Musetti gives Tsitsipas vibes to the max, he'll always be good and make random runs but I don't know if he'll legit inspire to do anything or even challenge Jannik/Carlos. Mensik is a wild card too, I prefer him over Fonseca who was just mentioned a minute ago but again super young and tennis is a tough sport to predict and why resumes matter so much when you're younger. The Miami Masters 1000 win v Novak is tremendous though
More random factoids:
Carlos is now 12-1 (!) in five set matches; Sinner is now 6-10.
Carlos has won the last five matches against Sinner. In four of those five matches, Sinner has won the first set.
In Sinner's last 50 matches, he is 47-3. That breaks down to 47-0 against the field and 0-3 against Alcaraz.
Sinner held serve against Nole 46 consecutive times before being broken in the semis here at Roland Garros.
Sinner had a grand total of two double faults for the entire French Open.