Hi,
AS Dark Mantis says, updating the BIOS won't actually remove the M.I.T. section but it will remove any changes you have made to the BIOS.
If, for example, you are overclocking, when you update BIOS all settings are restored to default values so, if you have made changes, it is a good idea to make a note of them so you can restore them once you have flashed BIOS.