This would help for sure. Ideally, the phone should stay in "expert mode" for a limited time only, like 1 hour.
However, there is still a danger that scammers will call after 12 hours, and they will be more convincing than educational material (or the user may not have read it).
> However, there is still a danger that scammers will call after 12 hours
It is unlikely it will work. Scammers are talking all the time and creating a sense of urgency, people have issues to think and listen at the same time, and they tend to drop thinking completely when in a haste. 12 hours of a break will give the victim time to think at least. Probably it will give time to talk about it with someone, or to google things.
However, there is still a danger that scammers will call after 12 hours, and they will be more convincing than educational material (or the user may not have read it).