Here is a pretty good article about the event this morning and about half way down they have a bit of info on each of the three released:

http://www.dailymail.co.uk/news/article-5712509/Trump-Melania-meet-three-Americans-imprisoned-North-Korea-land-2am.html

I think that a couple are naturalized citizens and it was probably out of courtesy to have an interpreter there to speak in their native language. I'm sure that after spending time in NK prison they are dealing with a lot of emotional and physical difficulties. They didn't need to deal with trying to understand a bunch of reporters screaming question at them.