My guess to what the GP is asking is if the files will still be downloadable from Apple even if they are not selling the tracks anymore. My reading of the article, makes the answer to that question vague, saying:

“But you can always go back and listen to the downloads, they always will work,”

Does that mean if you still have the files, they will work (which is obviously the case) or does that mean they are available to download at anytime once bought from Apple, but will not be available to be purchased in the future...

The re-download feature is actually relatively new (though my hazy memory is thinking it's probably more like 10 years old now...)

it will be interesting if apple removes downloaded media from itunes on the iphone. at that point I'm not sure how much value these would have.