The major update of the R6S will begin at 23:00 on June 10. As soon as it ends, it will be reborn as "Rainbow Six Siege X"

The major update of the R6S will begin at 23:00 on June 10. As soon as it ends, it will be reborn as "Rainbow Six Siege X"
 Ubisoft will start a major update maintenance for "Rainbow Six Siege" today (June 10, 2025) at 23:00, and will launch the service as "Rainbow Six Siege X" as soon as it is completed. The game will be free to play and a new mode "Dual Front" will be added that integrates offense and defense....

The linked article is in Japanese.