Hmmm .... would this be useful for IL2?
Quite likely, as long as the hit on frame rates due to animations isn't too heavy.
IL2 could benefit from static objects with moving parts - waterfalls and spillways with moving water, windmills, windsocks, flags, and trees which are blown by the wind, objects floating on water which rock with the waves, buildings which visibly collapse due to damage, etc.
While it might be too much work, the ability to have an object respond to some aspect of the environment - such as wind, waves, gravity, or bomb blasts - would be incredibly cool. For example, imagine that windmill in your example being able to change direction and blade rotation speed based on wind direction and speed.
The same concept could be used for fires or floods that spread to engulf and effect terrain objects, although the programming required to implement it might be excessive. (Imagine a Dambuster mission where your bombs could actually breach the dam, allowing you to watch the dam collapse, the reservoir behind it drain, the structures downstream getting swept away, and the landscape flood!)
A similar idea might allow for fully-animated vehicles, such as tanks with treads that move and turrets that turn.