Good manners are still important.
It has nothing to do with good manners as such, it's just a convention. I'm surprised American women haven't gotten rid of that one yet! Anyways, in Poland you never ever address the wife using the husband's given name.
E.g., if Alina and Jakub marry, and their surname is Nowak, then:
It is pani Alina Nowak and pan Jakub Nowak or, if addressed as a couple, państwo Alina i Jakub Nowak or Nowakowie / państwo Nowak / państwo Nowakowie.