Then they should take them away from those who haven't purchased yet...not from those who purchased the game at the time those extras were offered. In essence they paid for those extras as well, and taking it away from those who bought them doesn't seem right to me, tbh.
(I heard some here can still download games that were taken down for sale in the past, while others can't, so it is doable.)
I doubt they have the back-end structure to take away parts of game packages for sale while keeping it for download. In the case of a game no longer being sold, it's the whole package being affected. This would likely be the reason the Witcher 2 prerorder stuff can no longer be downloaded by us who did preorder it (and I stupidly deleted the file thinking I could get it again, then support confirmed it was no longer available).