It is only for Lumia 920, Lumia 820 and Lumia 620 developer devices.
To clarify, the OTA Developer Device Cyan updates for #Lumia we mentioned are for specific Developer Variants, not for those on dev preview
— Nokia Developer Team (@nokiadeveloper) August 18, 2014
Nokia Developer’s official Twitter account has mentioned that Lumia Cyan update for Lumia 920 devices running developers preview should be rolling out now OTA. This is bit confusing tweet as Lumia 920 in many markets haven’t yet received the Lumia Cyan updates and it has been limited to key European markets.
So, in our opinion, you can check for the update on your Lumia 920 running developers preview, but mostly it should come out only when Lumia Cyan for Lumia 920 is available in a particular market.
Anyways, the official Nokia Developer account also has revealed that Lumia 620 running Dev Preview will get Lumia Cyan starting next week and Lumia 820 from Sep 1st.
Earlier Joe Belfiore has also confirmed that all dev preview devices will ultimately get Lumia Cyan ( OEM Firmware) when it will be made available for them.