Superman does not look to be the priority of WB studio right now. And understandably so. A task for all the Superman fans just for fun. Say WB decided to keep Superman at hold. Let some time pass before the next shot on the big screen. And they decide to restart with a new actor. Flashpoint/Reboot clears the slate and if one so chooses, one can start afresh say sometime in 2022. And what's more? There is no priority of connecting it to any extended universe. Its Superman. Plain and simple. If one chooses to connect, its fine. But if one chooses not to, its your choice. Full freedom to craft your Superman onscreen. You have as much power as Nolan had on Batman Begins.
Fans who don't want a new Superman different from Cavill may choose to tell a further story if they wish to. (Its Flashpoint. Choose to keep none or all of it). But even they may try something different for a film coming out in 2025. Say, Henry Cavill is playing James Bond and he is not returning to the role. 'Just make a new Superman film as you choose.' And have fun while doing it. Its your show.