I think 14 days (x2) is way on the low side. To get reasonable file sizes they'd need a way to separate the map & the LOS map from the damage to the map , the units properties (there's a 1000 item array each) and the time scenario properties (how many - no idea) FOR EACH TICK of the engine (10th sec? 100th sec? Only send changes or send every time?), batch and transmit them all in a reasonable fashion over TCP/IP, load them, update the map and LOS map with the points above THEN expose it to input, store that input, de-interlace it all again, send it back to the calculating PC (for each tick), adding in the input to the first PC's player and then calculate the turn before doing it all again.
Or sumfink.
Either way, it's no easy task. I think (on zero information) that if they could have had it in for a months coding and testing they would have.
I also think (guess) there's no way it's going to be introduced in a patch. It's major functionality, not something you can "fix".
Me, I'm not bothered by it. In many hundreds of CM games I must have played 4/5 by WEGO TCP/IP. I'd get much more use out of an integrated PBEM handler.