The problem is, Senvion went out of business in 2019, and customers have been struggling to support their turbines. Apparently the Senvion design is exceptionally dependent on software access. Siemens and others have stepped in to offer support contracts to Senvion turbines in good working order, but with the opportunity to mine more lignite at the site, maybe RWE felt that it was time to spin down the Senvion turbines.
It seems like there may be many factors in this decision.