We can call this for any wireless system. Attackers could have a device transmitting on any frequency. Having detection devices relying on wireless transmitting is often a terrible idea.
More reason to go wired.
The only time I wouldn't be concerned is with remotes to arm/disarm. A decent system will have a 'rolling code' which is far more difficult to bypass.
What he neglected to mention is that a Simpli Safe, or Ring, system with a camera is also vulnerable. The camera is the same WiFi, and although not on the same 433MHz frequency, as the sensors it can be disabled by the third harmonic, the highest powered harmonic, of the interfering RF signal which renders the camera basically useless as well.
Nothing beats a supervised, hard wired, alarm system. Certainly more work, or more money if you don't DIY, but worth the cost if it actually becomes needed.
He was saying to check your cameras if you get an "interference alert". I'm saying that the camera, Simpli Safe or Ring, could have been disabled as well, especially with a 5 watt, or higher, inexpensive walkie talkie that throws lots of harmonics, like the one he had in the video.