I appreciate the last reply more than the first one. With the hint I finally found a formal declaration of the removal.
What's happening to RGA?
With the release of Open C/C++ 1.6, the Real-Time Graphics and Audio (RGA) API is no longer supported. Developers who want standard APIs for graphics should investigate the OpenGL ES APIs provided in the S60 platform. For UI development using non-Symbian APIs, developers may wish to explore Qt for S60.