Hey James,
You can use:
- ftp://
- http://
- https://
- file://
So no, FTP isn't required to download updates. Most people choose to use "http" because it's the fastest and easiest to use.
If you're talking about uploading your updates to your server then you can either use "ftp" or "sftp" (aka SSH FTP) within wyBuild -- or you can upload your updates manually. That means either use the interface your hosting service provides or use a 3rd party tool like Cyberduck.