Babylon has moving plants as well, animated by wind and/or player-npc when walked through. Moving flags, hanging window/door curtains etc...all setup with auroraflex properties. Not every plant/window/door but a large portion of them move.
Of course, Babylon is a tileset, no placeables involved, but the theory/artistry applies to placeables as well.
If the individual area has wind enabled, and the objects are not set to static, they will move according to individual settings applied to the vertices on the object itself. The stronger the wind, the stronger the movement, up to whatever the max is per object definition.