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. Spe

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.