If they will approve Bitcoin ETF, they would have to approve the ETH application soon and all other that will apply after it.
Taken from the fact that if the bitcoin ETF gets an approval, it will trigger the market to rise and in return the altcoins will follow.
Having alts to also apply for ETF is just a crappy idea since they just depend on bitcoin's trend, I hope its devs have some brains.
Though I don't see ETF good for bitcoin but for the price matter, it will be.