The answer to your question can be found in your communications and agreements with the bank, in relation to their approviing a short sale. If the correpondence, documentation, agreements, etc. require you to update your financials at any point prior to closing, or to inform the bank as to any change in your financial situation, then you must do this; but if the bank did not put any such obligation on you, you would not have to affirmatively provide this information...though if the bank specifically reaches out to you to ask if there has been a change in your financial situation, you would need to answer truthfully or potentially be committing fraud.