Imagine a situation in which a frightened, stressed user sees such a message on their screen. Meanwhile, a very convincing fake police officer or bank representative is telling them over the phone that they must ignore this message due to specific dangerous emergency situation to save the money in their bank account. Would the user realize at that moment that the message is right and the person on the phone is a thief? I'm not so sure.

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).

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.