WB Games Montreal says that their upcoming Batman game (without Batman) will lack "performance mode" and the ability to choose between it and "quality mode". Gotham Knights will also be locked to 30 FPS on consoles. According to them, it's because of the co-op and cooperative nature of the game. The information about this was posted on their own discord and has since been spread via, among other things, twitter by others. In other words, they haven't released any official information about this (yet).
Gotham Knights is unleashed on the world on October 21st, coming to PC, PS5 and Xbox Series consoles. The game was supposed to be released on Xbox One and PS4 as well, but the developers decided to scrap the idea of releasing Gotham Knights on last-gen consoles.