I am finding it hard it get any real time accurate information on this.
Not sure why an entire city is shut down.
Not something I can recall happening very much.

You are correct that banking and cc's should work fine.  I did read food supplies are a real concern for wuhan.

I do have this piece on info my wife spent 4 days in the hospital with 2x pneumonia she is home and okay. Our local hospital  has 284 beds 215 were filled with pneumonia-flu victims. This was jan 13 to jan 17.

Howell New Jersey is 10000 miles from Wuhan, China yet we are having lots of lung disease. Nurses and doctors told.me it has been the worst they ever seen.