Bank of America’s commitment to set aside $20.4 billion to address a big chunk of its exposure to the mortgage debacle it acquired when it bought Countrywide Financial may point toward evolving new servicing standards for the industry at large. But officials acknowledge that it’s hard to estimate the risk of future buyback costs, especially as the policies of Fannie Mae and Freddie Mac continue to change and other litigation – including nego-tiations with state attorneys general – is still pending. BofA agreed to pay $8.5 billion to settle representations and warranties claims and ...