Yes, some schools do interview that late, although most are finished in March or April. I bet that with all of the AMCAS problems this year, many schools will interview later than they have in previous years, so I wouldn't be suprized if lots of people are interviewing in late spring/ early summer.
As for acceptances, LOTS of people get accepted all through the summer. Schools accept people up until the first week of classes! They take people off of their waitlists as spots open up in the class.