An fcpbunlde file, is essentially, a folder. What you are seeing is normal on a file system that doesn’t have fcpx installed (such as cloud storage, or any Mac that does not have FCPX installed).
I would, as best practice zip library files and have those backed up as you suggest. This will ensure you have everything you need. Sometimes, since the amount of change is so subtle, all of the latest little files do not get backed up to cloud storage in the bundle folder, which would result in an incomplete backup. A zip files will ensure you have the latest backup, at least at the time of zipping the file.