The video takes a long time to say this:

There's a new (and concerning) service known as "Plist FMI off" which appears to be able to unlock an iPhone that would otherwise be locked and useless to thieves.

Disabling iCloud lock / Find My iPhone lock should be something only possible by someone working from inside Apple -- thus implying that there's likely an insider involved in this. Or at the very least, a security flaw in Apple's network that's allowing this to happen.

The Youtuber seems to think that Apple should be forthcoming about declaring this vulnerability exists. IMHO, he is wrong to think that. Declaring the flaw before it's been patched would only create a rash of iPhone thefts.

Ideally, Apple is now aware of this situation, and is doing internal investigations to correct it.