Where did my recently added and recently played playlists go?

I synced my iphone a few weeks ago, strictly to transfer purchases from my phone to my pc. However, for some reason, the playlists recently added, recently played and top 25 most played were all removed from my iphone. These were my favorites! Since then, I've transferred and synced to a mac, but those 3 playlists aren't going to my phone. I also have 2 playlists on my phone which won't go to my mac. What's going on? When I tried to sync music, it says "Are you sure you want to sync music? All existing songs and playlists on the iPhone will be replaced with songs and playlists from your itunes library." All my songs appear to be in itunes, so I'm not sure that it's a problem, other than that I might lose those 2 playlists which wont transfer off my phone 😟