It seems that there are three challenges in doing the choir that are huge -
1 - the money for all those singers
2 - making them all lose their voices for the legato recordings
3 - inventing a new technology for samples to form complete words that will fit seamlessly into VE
So it is understandable that it will take almost as long as the entire orchestral library did, or MIR.
Though I am just as impatient as anybody. I still cannot believe that EW did not record the entire range of each choir in the Symphonic Choir. That burns me up (especially after buying the damned thing). Do you realize they took a one step forward and two steps backward from VOTA? Because that earlier choir (which I also have) had complete ranges on SATB, and could also do word formation, though neither does it very well. And nobody in the world has recorded real legato which, besides intonation, is the single most important element in singing. There is nothing worse than hearing a sampled choir pinging from one single note sample to another...