Hi there,
I don't know why the BIOS has been removed but it could be because a problem has been discovered or that they are preparing for the next update. If you have a problem you should be able to re-flash your BIOS with the FC version but, if everything is working OK then you could wait for the next official update. Personally I would probably revert to the FC just to be on the safe side.
There has been another case of a BIOS update being removed and this was because Gigabyte discovered a problem with the update process, if I remember correctly.