AFAIC, reflashing BIOS won't give you anything, you need to sign it first with proper private key which is checked by the CPU hardware before execution begins. This EMI trick fools CPU itself and I cannot see how it can be fixed, unless new paging algorithm is invented.
This specifically is trivially defeated by ECC, though it wouldn't be that much harder to instead flip 3 bits and ECC would be unable to help. ECC has very poor penetration outside the server world though, so we're still safe. For now.
I've thought a little bit more about this case and came to conclusion that to mitigate this attack paging agorimths can be improved by using redundancy and CRC checks with not too much overhead. Yet it takes a lot of work and investment, so it won't happen any time soon. Yes we are safe for now.