Since this is an .ipa file from a third-party source (not Apple), there is no guarantee the code hasn't been modified.
This specific filename, download-whats-app-messenger-v22-v406834304-64bit-os120-ok14-user-hidden-bfi2.ipa , is the digital footprint of a (specifically an .ipa for iOS devices) that has been extracted and archived by a third-party source. The Story Behind the File
Older versions of WhatsApp lack the latest security patches and encryption updates.