https://www.seat61.com/news.htm
Short article in French - https://bx1.be/categories/news/le-train-de-nuit-nightjet-reliant-bruxelles-a-berlin-ne-roulera-plus-des-la-fin-mars/?theme=classic
Edited to add:
https://www.euronews.com/travel/2025/03/24/off-the-rails-night-train-from-berlin-to-brussels-will-stop-running-at-the-end-of-march