If the US goverment says don't allow the 2 states access then that's what that company is going to do or they will risk being shut down completely. I imagine that each member probably got a email telling them of the reverse of membership allowance and Coinbase asked them to withdraw all coin before a deadline.
Well I think Bitcoin is a worldwide popular currency and now is using in all huge States and also in a lot of market so in this case making any prediction about it is just a fault. I don't think Coinbase going to be doing randomly without any sort of Investigation on other parts, that simply could be a claim without a bit of reason. if they were doing this kind of act, they would may be face a ton of law suits and regulation from the state government which is highly doubt they gonna want. its now their task to ensure that something illegal is not going to happen with the money invested.