Yes - and that is a major reason NOT to purchase the CT15 because the Festool cyclone would not attach to it!
For me, I already had the HD bucket lid and wanted to use that with my CT15. The orange Ridgid hose works great with the CT15. All I had to do was trim one end of the connecter to fit in the lid of the extractor. The bungee cords on top were just long enough to keep the Ridgid hose neat. Now, I am not planning to heavily invest in Festool products to the point where I would need the systainer attachment. A teacher salary limits those kinds of shop investments.