I’m going to play nice with Packard here.
The video of course is disinformation, but not in the sense of outright lying as much misrepresentation through omission. The Democrats, even centrists, have never actually advocated for cuts to social programs, but it was a common ploy between the ‘70s up to the start of Clinton’s presidency to push sunset legislation as a way to both show that Democrats were moving away from their progressive elements and force Republicans to address their own attempts at cutting those programs.
In the video, Bernie isn’t trying to get Biden to say he’d changed his mind on social security and Medicare as much as force him to admit that he’s not a progressive standard bearer… something we all knew anyway.