No. Your Creative Cloud storage is not a replacement for hard disk space. It's an auxiliary space for syncing to other devices and sharing assets with colleagues. Also do not confuse Creative Cloud storage with dedicated cloud backup & disaster recovery systems like Backblaze, Carbonite and others. They are completely different things. See Creative Cloud Storage help below.
I don't believe it is possible to have files Only On the Adobe Cloud servers. Even if you logon to the Creative Cloud website and Drag and Drop files there from any folder on you drive and also have the Sync feature enabled they get RE=Downloaded to the CC Sync folder on your drive.
Sure if you turn of the sync option, actually Pause it as you can't turn it off, but then the only copy of your files is in the Clouds.
Also IF you cancel your subscription all those files will be deleted.