On most rolling stock, those same posters will try and portray it as a last resort. Many explicitly say something along the lines of, "It is safest to stay on the train where possible."There a posters that encourage the option of escaping on to the track in an emergency. I don't see what the risk is? Danger of being hit by a stationary train?
While I sympathise with those who chose to voluntarily detrain, I would not encourage it. There's a lot of dangers on the railways, even if your train has been stopped for ages. Ordinary passengers are not trained in what these hazards are and how to mitigate against them. Everything from oncoming trains to electrified rails to trip hazards.