Posters should remember that not every interview is actually an interview. Jerry will often interview someone just to learn more about an opponent, its something Al Davis used to do and Jerry learned it from him.
If McCarthy really will take the Giants job, there is real value in interviewing him to get insights into his strategy, etc. McCarthy and Lewis have been around the NFL for decades, no matter who ends up as the new Dallas HC the franchise will gain valuable information from interviewing these two guys.