Originally Posted by DaveyDandry

The boothlings don't know and don't care how you got your status. When your FC affiliation goes away, so does the Diamond card status and you revert back to whatever level you actually earned. You can carry your diamond card around till the end of time, but your perks will be based on your actual status. I have two friends that were diamond through FC and within two weeks of letting the FC lapse, both were reverted back to their lowly gold card status.