deleting the cbhc title while it's installed will brick the system. afaik, it's not even possible to delete the game, only by formatting will it brick. if you uninstall cbhc, you can redownload the exploited game from the eshop. however, it might fail at install immediately, because of the fake ticket you originally had. that's why I wrote the tutorial in my sig about fake tickets. I did uninstall cbhc once, because I didn't want yoshi's island to be the game I was exploiting. I now have brain age as my cbhc title. I think the game will still work, even after cbhc, if you copy the game. I'm not sure if it's usb that takes precedent over the internal flash or if it's the fake ticket causing this to occur, but I have the original title/icons for redNAND still present after installing cbhc. basically, you'd have two copies of the game installed. I have no idea why nintendo did this, unless they were thinking about people wanting to copy content over to a larger drive.
If your console is running Luma 10.2.1 or higher, it is 100% safe to update. You can check your Luma version by holding (Select) while booting your console.
If your console is on an older Luma version, you should update Luma before you update your console to 11.17.0.