There are so many situations that require certain documents to get anywhere, most of them unpleasant and unexpected. This is why it’s important to have everything organized ahead of time so you’re not searching through the basement or waiting in line in a government office for hours with a recent emergency bearing on your mind.
But keep in mind this may be a time of loss for your parents. While you may have the best intentions at heart, they may not take it as such. Pick your battles, with so much already changing for them, the idea of organizing paperwork can seem like a much bigger deal than it may to you.
Before doing anything, talk with them about why you want to get their papers organized. It can also help to do this together, even if it slows down the process.