Nothing will be lost however, as all of the news articles, forums and groups were imported into the current Bungie.net back in 2013.
Bungie's last Halo game was Halo: Reach from 2010, which means 343 Industries has now been responsible for the Halo series longer than Bungie. But there are still a few signs of Halo life at Bungie, with the page Halo.Bungie.net as the most obvious thing. But now that is about to come to and end.
In a new blog post from Bungie called 'Dust and Echoes', they now reveal that is is time to say goodbye to Halo.Bungie.net as it will be removed entirely on February 9:
"Almost nine years ago, stats and files from our previous franchise, Halo, stopped getting updated on Bungie.net. Since then, all stats, files, and other data from Halo 2, Halo 3, Halo 3: ODST, and Halo: Reach have lived on in remembrance at halo.bungie.net.
On February 9, the halo.bungie.net website will be taken offline permanently. Everyone is welcome to save their stats and files, however they can, if they'd like to save anything. Please keep in mind that our News articles, Forums, and Groups were imported into the current version of Bungie.net back in 2013."
With this, the last public sign of Halo life from Bungie is gone, although we happen to know for a fact that they have a huge Master Chief statue at their office.