I think Roberto or Don were running a thread some time in the past that was suggesting that PG team should probably up the default from 32 to 64 or more. Therefore, I am guessing, aside from being difficult to remember such_a_very_very_very_long_name_of_a__function, there should be no impact.
OTOH, we end up with long names because we convert
package_name.{function|procedure}_name[.{argument|variable}_name]
(each of which may well be within 31 characters limit into a single string (albeit shortened at times for readability):
package_name__{function|procedure}_name[__{argument|variable}_name]
