

Any service you use passkeys with instead of passwords won’t put you in another leaked password database. The public key just needs to be invalidated and you can move on with your life.
Does it though? Is there anything wrong with your public key being, um public? All they can do with it is verify who you are, (or technically encrypt things that only you can read - not that pass keys are used in this way?).
If you want to be safe backup anything you care about before hand. Assume that you might end up needing to wipe the system and reinstall everything. Encrypting the Linux partitions should not affect windows but there are so many other steps that could go wrong when partitioning and installing a system it is better to backup everything you care about just incase.