You DO know that ETC is an ethash coin, and therefore the E3 WILL mine it?
The ETC will stay PoW, so it has more urgency to change the PoW to be more ASIC resistant. It is about 3.3% of the total hash of ETH.
I think about 40-60% of the current ETH hash is ASIC as around 60-70% of the Monero hash was ASIC. The Monero original hash is about 840MH/s while the V7 hash is about 250MH/s now.
So if ETC changes, it will attract more GPU miners and could raise the price of ETC.