JP Morgan aren't against Bitcoin. They like anything that makes profit. Their CEO just manipulated the market by saying it's fraud and later JP Morgan bought huge amount of some Swedish BTC fund for cheap.
But it's true they're part of Ethereum Enterprise Alliance. And they also have agreement to build their private sidechain on ethereum.
From where I am seeing JP Morgan rather Jamie's remark about bitcoin, he is definitely not praising it. His statement was actually a disturbance to the new investors but didn't really afraid them because now millions are trusting bitcoin.
By the way, this story has become an ancient one now. BTC has already beaten him up. No one can destroy bitcoin and there are ways to do business without playing cheap tricks.