Feistel-Network - why wire crossing? In Feistel-Network, there would be a wire-crossing at the end (for the next round). Which insufficiency would occur, if the wire crossing would be omitted?
Let's look at a picture of a generic feistel cipher



Notice that no keying material is used during or after that final swap. So, we can conclude that the final swap does not impact security at all.

So, why include it? It is so that all rounds will be identical. This could help with some implementations. That is all.