You can still play your old MP3 files, but the format that owned the early days of digital audio is done.
“The Fraunhofer Institute for Integrated Circuits recently announced that it and Technicolor would no longer license “patents and software” for the MP3 format. The licensing program officially ended on April 23.”
“The impact on you at home: While MP3 licensing may be going away, the everyday use of MP3s isn’t going anywhere. MP3 files will continue to play as they always have, but like any technology, it will slowly fade away as more advanced options (such as AAC) become more widespread.”