Oh that's not true at all! I've purchased old iTunes albums that have been pulled off the (iTunes) cloud simply because the label/distributor/producer decided to make them no longer available to iTunes. This doesn't happen often, but it has happened.I never download them. Why should i, since they are always available in the sky, and that being the newest version even?
And besides…. how expensive or difficult is it to simply archive all your downloaded iTunes files in a single storage medium? A Firewire drive? A Time Machine backup drive? A USB thumb drive? All of my iTunes purchases fits easily inside a 64GB USB thumb drive. It's not hard.