I've encountered this as well. When I cite a FS source, I usually include both the record/index link and the image link (if there is an associated image). For the problematic sources that I've encountered, the record/index link shows "This Record has been removed.", but the image link still works. On the image page, you can use the Image Index tab (lower left) and scroll to the individual in question and click the record icon next to the name to get to the current iteration of the record/index link.
I don't plan to make any changes to the existing FS source citations until they determine what the problem is and what the resolution is.