Comment by M95D
From what you know about WA, is it possible for the servers to MitM the connection between two clients? Is there a way for a client to independently verify the identity of the other client, such as by comparing keys (is it even possible to view them?), or comparing the contents of data packets sent from one client with the ones received on the other side?
Thanks.
No.
Whatsapp uses key transparency. Anyone can check what the current published keys for a user are, and be sure they get the same value as any other user. Specifically, your wa client checks that these keys are the right key.
Whatsapp has a blog post with more details available.