I Just got Lumia Cyan update yesterday with Mexican Operator Telcel. To this date there are phones without Lumia Black from that carrier, but they released Lumia Cyan incredibly fast.
To anyone that hasn't received the black update, go to Telcel and make them update your phone, they are going to tell you that it's going to be under your responsibility if it doesn't work correctly, but it does work. I did this with both my phone and my wife's phone (Both are Lumias 625). You will lose all your info, but since you need Black to get Cyan this is a good option, instead of waiting for God knows when for Telcel to release black and then Cyan.