I think it's a new game that is being written, with models and maps from the COD game, but I would hazard a guess that it is installed on top of the existing one anyway. That explains why this is taking so long and why some things will be missed out on COD. If you are expecting everything in COD to be fixed standalone I don't expect that, and that's no different to the first IL2 - you had to buy sequels for changes and more kit regardless of what you thought of the first game + patches.
We know that the netcode sucks, it's refreshing to know that it was ripped up and started again. I just hope that it's not going to suck like the current one does
I feel burned, personally, so I'll definitely wait to see the response of the community before buying the sequel. I'm not going through this again.