iTunes Match music on iPhone appearing as not downloaded.

I use iTunes Match to access my iMac's iTunes library on my iPhone where I download a lot of it (about 5000 songs) for offline listening. Clicking the download icon on this much content takes a lot of time on my iPhone, which is why I was disappointed to notice that almost all of this content is now only in the cloud. I can still see the content, but the downloads have been removed and everything now has the cloud icon with a down arrow.

Any thoughts on how these downloads were removed? Is there a way to get them back without spending 2 hours downloading the content again?

Thanks!