That doesn't help much. If people were told they were going to be murdered in a painless way (or something not particularly painful - for example, a shot for someone who isn't afraid of needles and has no problem getting vaccinated) most would consider this a threat and would try to avoid it.

I think most people's practical attitude towards death is a bit like Syrio Forel from Game of Thrones - "not today". We learn to accept that we'll die someday, we might even be okay with it, but we prefer to have it happen as far in the future as we can manage.

Signing up for cryonics is an attempt to avoid dying tomorrow - but we're not that worried about dying tomorrow. Getting out of a burning building means we avoid dying today.

(whether this is a refinement of how to understand our behaviour around death, or a potential generalized utility function, I couldn't say).