At the rate the Middle East is picking 777Xs off the shelf, there won't be any delivery available for CX (or anybody else) for years. Unless they pay a premium...
Very true. 259 initial 777X orders from only 4 companies. Assuming they can get 4 a month through the production line (probably not likely), that's about 5 & 1/2 years. At 3 a month, that's just over 7 years, until anyone else can get one (unless they pay a premium to one of those carriers as noted). By that stage, there'll be talk about a 777-superX, or a 350-1000X, or maybe something new.....
The numbers quoted are staggering for EK alone. 50 x 380, 150 x 777x. CX barely have 150 aircraft total at the moment, let alone 150 of a single type.
I'm sure that it's been noted somewhere before that many of these will be replacements for EKs 777-300ERs. On the issue of no 777Xs being available, pretty much the only way to get a 777 will be to get a 2nd hand -300ER from one of the -X launch customers.