I had this same issue while switching from pc to my new macbook. I contacted EA help and at least four people was sending me emails regarding the case - asking same questions I had already answered. And after sending a long email explaining the situation and giving all the same information over and over again they closed my case leaving me with no answers...
Today I opened the chat to EA help and finally got some service from the helpcenter. It took a while but after all I got these three add ons to show up on my EA App and downloaded to my Mac.
So there is hope to get those back!
I chatted with EA Help tonight and they were able to resolve my "Available on Windows" DLC issue - they did some magic, the DLC showed up, and I was able to install it!
