I can't post a link because I'm new here, but go to: www dot microsoft dot com, and open /en-hk/mobile/support/product/lumia1520/softwareupdate/
It says cyan. If you open the update tracker, check for HK, it says denim. Some are blaming the carriers on other forums, but I think this is an MS problem. And it's also not the carriers fault that MS announced something in December, told the users that flagship phones (1520 and 930) gets the update first, then after 2 months, tell the users that it's available when it's not.