Notes on MacOS Sierra
No.  They are gone.  iCloud, for a lack of a better word is a "sync conduit" between your devices; it's not a backup.    This means that a change you make on any of your devices is what gets synced.

When you restored the 1 week old backup from Time Machine, more than likely, Notes did a sync which overwrote what was on iCloud because it "assumed" that was the latest data to be synced.  

What you should do in the future....prior to upgrading your OS do a manual Time Machine backup so it saves the latest state. This way you know for a fact that what you restore is your most recent version.