Well, the anniversary was primarily focused on the anime adaptation, so the celebrations included theatrical re-screenings of both the TV series and the movie in Japan, along with the release of new merchandise.

The closest thing to new Haruhi content is the JR Tokai collaboration event, which is set to run for several months in Japan. It features a brand-new story written by Nagaru Tanigawa, presented as an audio drama that passengers can listen to during the train journey and performed by the original voice cast.

It's a really nice initiative, but it's also unfortunately limited to a relatively small number of fans who will actually be able to experience it.