Some new official info from ubi forums

[The Kraken]

Originally Posted by Zorin

Indeed, especially with Oleg stating that the formation dynamics are scalable and that planes further away from the player are simplified in terms of mesh AND flight model.

Maybe another big improvement that was sent to the back burner?

I was (actually for years now) waiting for official info on that aspect, but never found any word from the devs, so I don't consider this another "promised feature". If all planes on the map have the full flight, damage and AI models (with all the pros and cons of that approach) it's obvious that we won't get several hundred planes at once in a mission. A bit unfortunate that the Battle of Britain is the starting point for this new series, because some Eastern front scenarios wouldn't suffer much from such a restriction.

On the other hand it's nothing that raw CPU power won't fix on the long run.