Will I need a BIOS update for the MSI GAMING 5 Z97 with the i5 4690 Haswell?
You don't need a BIOS update for the MSI GAMING 5 Z97 to support the i5 4690. It should work right out-of-the-box. All H97/Z97 Chipset based Motherboards support all Haswell Refresh without any need for BIOS updates.
Will I need a BIOS update for the MSI GAMING 5 Z97 with the i5 4690 Haswell?
You don't need a BIOS update for the MSI GAMING 5 Z97 to support the i5 4690. It should work right out-of-the-box. All H97/Z97 Chipset based Motherboards support all Haswell Refresh without any need for BIOS updates.