That's highly unlikely. If you're not on a shared computer, it's even less likely.
You can add HashKnownHosts no to your ~/.ssh/config to disable hashing the host names, then purge your ~/.ssh/known_hosts file, and then re-populate it over time as you log in to your various remote hosts. As Jasen answered, you'll have to repeat the process of accepting them ...
Known hosts usually has hashed records and some services that it is used for (eg: github) have multiple servers resulting in multiple records in the file.
You can delete the file and re-generate a new one, that will mean you'll get alerts from ssh for each server.