According to the official website, a collaboration project of Seitokai no Ichizon
and Boku wa Tomodachi ga Sukunai
was announced to be launched. As the first collaboration, each of the authors of the original novels will write a joint novel of the two works. The remaining contents of the project will be announced later.
Seitokai no Ichizon x Boku wa Tomodachi ga Sukunai Collaboration official website
It's unusual that a collaboration between two different publishers is realized. Media Factory, the publisher of Haganai, has recently been acquired by Kadokawa Group Holdings, the parent company of Ichizon's publisher Fujimi Shobo. That may be the background of this collaboration.
Details of the new Seitokai no Ichizon anime
have not been revealed yet.