From the press release:
The Read and Publish, ‘transformative’, component of the agreement, effective immediately, entitles authors to publish immediately OA in Springer Nature’s collection of 1,900 ‘hybrid’ journals and provides participating institutions with permanent access to Springer, Palgrave, Adis and Macmillan journals in the Springer Nature portfolio. The Publish and Read (PAR) fee will be €2,750 for each article published and will be paid from central subscription funds.
So two regressive institutions—the APC and the hybrid journal—are propped up. And German authors have automatic OA citation/visibility benefits denied to most authors elsewhere. Transformative?