I guess a scammer can sell it as "we're buying something significant [another company?], this will affect our share price if the info goes out, so you need to sign this NDA and keep this quiet, you're only 1 out of 10 people who knows this...".
They could also sell it as payment for an e.g. consulting firm for the above secret deal...
Most people historically would consider a video call with the person to be sufficiently authenticated. Yeah, that has changed obviously, but it has changed like today.
No, not today. This has already happened a few times. And even before it happened people warned about this predictable use of the technology. There has been enough time to update policies. Even $employer already did, and I consider their security policies so-so.
They could also sell it as payment for an e.g. consulting firm for the above secret deal...