it will be very hard for them to open new bank accounts...
What makes you think so?
If you ask me, if even half of all that frenzy with and around Bitcoin in Japan has any connection to reality, they should have no particular problems to establish payment channels through Japanese banks. Obviously, that may take some time (maybe, even months) but they will have to walk this way in any case if they want to keep the exchange afloat and not lose their clients, which may get bored waiting for fiat withdrawals. Though I don't think that at other exchanges it is any better than that, especially if the question is about millions of dollars
One of Bitfinex's problems is that they haven't registered all their activities properly. It will be difficult to sign up at a Japanese bank knowing that they have legalized Bitcoin recently. If Bitfinex doesn't show any willingness to change that, their only chances will be to look for banks ignoring all these regulations, which at the same time must offer the same functionality in terms of accepting incoming and outgoing transactions nominated in USD.
"banks ignoring all these regulations" means that those banks may be banned as well. all the USD wires are going through few big american's banks(correspondent banks). once bitfinex is banned, it will remain like that.
Bitfinex MUST get a financial license otherwise they are doomed.
