So, while installing Bazzite, we enrolled some MoK keys, using universalblue as password.
If I want to uninstall Bazzite in the future, do I need to remove these keys, or do I have to remove them? How do I remove them?
Would they cause any problems if I keep the keys and then reclaim the drive for windows (I am dualbooting Windows and Bazzite on an Asus laptop), or install a new linux distro on that drive?
The MOK is stored as an EFIVAR in the firmware of your motherboard.
The MOK is loaded by shim and will be added to the Kernels keyring. This means the kernel will trust kmods signed by the MOK. Additionally shim will tell grub to load Kernels signed by the MOK.
If you uninstall Bazzite, you can remove the MOK since you do not need to trust things signed by us. You can remove the key using mokutil.
Will it break windows or anything else? Nope. Windows will ignore it. Other Linux distros may load it if they have shim.