I don't see what the problem is. If I recall correctly, the videos application was developed in-house before the platform was ever released to third-party developers. Because videos and other applications started building their own walls, facebook opened the wall for platform users. This is a good thing for developers, not a bad thing.
The statement that "Facebook engineers will detect it, copy the functionality, and render your app pointless" is a pretty wild claim to make without backing it up with evidence.
The complaint is not about Video, but about enhancements to the Wall made recently which were clearly based on 3rd party apps. I think that's evidence enough to make the statement. I just saw a Techcrunch write-up of Superwall the other day. I'm sure they're less than happy about being encroached upon.
The statement that "Facebook engineers will detect it, copy the functionality, and render your app pointless" is a pretty wild claim to make without backing it up with evidence.