Of course. Why would they show you their proprietary code for a totally unnecessary app?
Alternately, you can grab the binary from the .ipa and decompile it. Objective-C/Swift code effectively can't be symbol-stripped; objc_msgSend takes a string selector, and those selectors remain evident in the binary. (This also makes writing cracks/keygens for Obj-C apps very, very easy.)
Or you can just uninstall the app.
Well, Facebook is hiring ;-)
The easiest answer is to just not let Facebook anywhere near your phone.