This shouldn't hold water and this story isn't complete.
A cash advance is a way to get around chargeback the concerns with credit cards, which is the leading problem when paying with a credit card and sending someone an immutable currency. JPMorgan, like Coinbase (also does this now), if faced with a chargeback and don't win, lose out on the money if they're unable to recoup it from the customer they sent, say, Bitcoin to.
RE: JP Morgan Sued For Overcharging Fees on Bitcoin