Yeah it's happening for everyone .. I remember that Daniel Rubino said before that if we wanna know the REAL latest OS on the phone with it's features we need toggle off PFD and see Extras+Info.
I think it is normal. I have it too on my 820 with Cyan.
Once I disabled the developer preview, I was on Denim.
I think it is because the developer preview is a "beta" of the Denim release. Disabling the developer preview, you aren't back on Cyan but have still the developer preview installed until the official Denim is released on your device.