I heard from someone thats usually dead on when they have a restock and what sizes and everything why they actually pulled the release.
Apparently there was some type of hole in their system that has always been there that allowed folks to have the shoes in cart a short time after they loaded the sizes to their website.
It sounds believable because i always see someone on twitter with info about restocks and such because they run some type of program that shows what sizes of certain product numbers were loaded to NDC.
ive also seen them go back and forth about what is and what isnt on the website because nike will load sizes, then take them off. (or something like hat.
Dont take this as the actual reason, because i dont know and it could be all BS, but with the way royals and breds go for hundreds more than retail, i can see folks that know about the exploit getting greedy and taking advantage of it and causing nike to take steps such as this.