From the title of the post, I thought it would be about how not signing up gives you certainty. I've read someone who doesn't want to sign up say that dying in a normal way would give their family peace of mind.

In terms of whether it's a benefit, if it does motivate you then it's a good Dark Arts way to stop putting off signing up. However, cryonics companies changing their image to take advantage of it strikes me as a really bad idea for the reasons in Ander's post.