I don't know. I would guess no.
I would check that you indeed have recent backups. Then remove the LiveID. If you don't like the result for any reason, restore the backup that preceeded your making the change. File->Restore is the undo mechanism.
You could ask CheckFree, which actually runs the service, but just trying it seems easier.
While you are thinking about backups, you might want to increase the number of backups that Money retains. Plus check that your scheduled backups are to different media, such as a flash drive. It's always a good idea to review your backup procedures.
After removal of the LiveID, consider if you want to apply another passwording method on your files.