That board does have a BIOS flash button, so you can update the BIOS without needing an older generation CPU. Check the manual for the exact procedure (and don't forget to unzip the BIOS file, I've totally made that "oops" once.)
Any time you're flashing firmware on a device, an interruption in the flash process can brick it, so try to do it in the safest way possible-- i.e. make sure you're plugged into a good secure power outlet where the cord won't fall out or get bumped, nobody in the house picks that moment to turn on Every Single Electrical Appliance and trip a breaker, etc. If you have an Uninterruptible Power Supply, this would be a good time to use it.
I've flashed a couple MSI boards like this, one additional caveat is that both times I had the computer fully assembled, and it did boot up on its own after the flash process was completed. So make sure the CPU cooler is installed, nothing's blocking the fans, that sort of thing