What kind of movement/flow are you looking for specifically? Do you refer to ocean waves?
Ocean waves are actually planned
But unfortunately we have no ETA for that yet... it will happen after replacing the Java version with the new version.
If you're looking for flowing water, the new version already has flowing water, but it only takes terrain into account for collision for now. The only change that's planned is that water will also detect construction elements in the future (at least construction elements with a minimum size).
Water has a fixed resolution (one water cell has the size of a block), unfortunately it's not possible to have more detailed water (i.e. consisting of much smaller cells/blobs) in a performance-friendly way...
Having detailed flowing water on a large scale isn't possible (yet) from a technical point of view unfortunately. If a single water drop would have the size of 1 cm (which is still a big water drop), a tiny 4x4 pond would already consist of millions of water drops. While modern GPUs can actually handle this on a small scale in realtime, this is far from being usable in a game like RW. On the one hand, the game needs this on a larger scale (what if the player wants to have more than just a tiny pond of physically accurate water?), on the other hand, this data needs to be accessible by the CPU (because the game has to sync the water state between clients in multiplayer, and it also has to store the water state on the hard drive, so it doesn't get reset everytime you restart the game/server).